The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.
Regulatory signaling systems that control the progression through the CELL CYCLE. They ensure that the cell has completed, in the correct order and without mistakes, all the processes required to replicate the GENOME and CYTOPLASM, and divide them equally between two daughter cells. If cells sense they have not completed these processes or that the environment does not have the nutrients and growth hormones in place to proceed, then the cells are restrained (or "arrested") until the processes are completed and growth conditions are suitable.
The period of the CELL CYCLE preceding DNA REPLICATION in S PHASE. Subphases of G1 include "competence" (to respond to growth factors), G1a (entry into G1), G1b (progression), and G1c (assembly). Progression through the G1 subphases is effected by limiting growth factors, nutrients, or inhibitors.
Phase of the CELL CYCLE following G1 and preceding G2 when the entire DNA content of the nucleus is replicated. It is achieved by bidirectional replication at multiple sites along each chromosome.
A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.
A large family of regulatory proteins that function as accessory subunits to a variety of CYCLIN-DEPENDENT KINASES. They generally function as ENZYME ACTIVATORS that drive the CELL CYCLE through transitions between phases. A subset of cyclins may also function as transcriptional regulators.
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
The period from onset of one menstrual bleeding (MENSTRUATION) to the next in an ovulating woman or female primate. The menstrual cycle is regulated by endocrine interactions of the HYPOTHALAMUS; the PITUITARY GLAND; the ovaries; and the genital tract. The menstrual cycle is divided by OVULATION into two phases. Based on the endocrine status of the OVARY, there is a FOLLICULAR PHASE and a LUTEAL PHASE. Based on the response in the ENDOMETRIUM, the menstrual cycle is divided into a proliferative and a secretory phase.
The period of the CELL CYCLE following DNA synthesis (S PHASE) and preceding M PHASE (cell division phase). The CHROMOSOMES are tetraploid in this point.
A cyclin-dependent kinase inhibitor that mediates TUMOR SUPPRESSOR PROTEIN P53-dependent CELL CYCLE arrest. p21 interacts with a range of CYCLIN-DEPENDENT KINASES and associates with PROLIFERATING CELL NUCLEAR ANTIGEN and CASPASE 3.
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
A cyclin-dependent kinase inhibitor that coordinates the activation of CYCLIN and CYCLIN-DEPENDENT KINASES during the CELL CYCLE. It interacts with active CYCLIN D complexed to CYCLIN-DEPENDENT KINASE 4 in proliferating cells, while in arrested cells it binds and inhibits CYCLIN E complexed to CYCLIN-DEPENDENT KINASE 2.
Product of the retinoblastoma tumor suppressor gene. It is a nuclear phosphoprotein hypothesized to normally act as an inhibitor of cell proliferation. Rb protein is absent in retinoblastoma cell lines. It also has been shown to form complexes with the adenovirus E1A protein, the SV40 T antigen, and the human papilloma virus E7 protein.
All of the processes involved in increasing CELL NUMBER including CELL DIVISION.
CELL CYCLE regulatory signaling systems that are triggered by DNA DAMAGE or lack of nutrients during G2 PHASE. When triggered they restrain cells transitioning from G2 phase to M PHASE.
A quiescent state of cells during G1 PHASE.
Phosphoprotein with protein kinase activity that functions in the G2/M phase transition of the CELL CYCLE. It is the catalytic subunit of the MATURATION-PROMOTING FACTOR and complexes with both CYCLIN A and CYCLIN B in mammalian cells. The maximal activity of cyclin-dependent kinase 1 is achieved when it is fully dephosphorylated.
A cell line derived from cultured tumor cells.
Regulatory signaling systems that control the progression of the CELL CYCLE through the G1 PHASE and allow transition to S PHASE when the cells are ready to undergo DNA REPLICATION. DNA DAMAGE, or the deficiencies in specific cellular components or nutrients may cause the cells to halt before progressing through G1 phase.
Nuclear phosphoprotein encoded by the p53 gene (GENES, P53) whose normal function is to control CELL PROLIFERATION and APOPTOSIS. A mutant or absent p53 protein has been found in LEUKEMIA; OSTEOSARCOMA; LUNG CANCER; and COLORECTAL CANCER.
A key regulator of CELL CYCLE progression. It partners with CYCLIN E to regulate entry into S PHASE and also interacts with CYCLIN A to phosphorylate RETINOBLASTOMA PROTEIN. Its activity is inhibited by CYCLIN-DEPENDENT KINASE INHIBITOR P27 and CYCLIN-DEPENDENT KINASE INHIBITOR P21.
A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.
Protein encoded by the bcl-1 gene which plays a critical role in regulating the cell cycle. Overexpression of cyclin D1 is the result of bcl-1 rearrangement, a t(11;14) translocation, and is implicated in various neoplasms.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The process by which a DNA molecule is duplicated.
A 50-kDa protein that complexes with CYCLIN-DEPENDENT KINASE 2 in the late G1 phase of the cell cycle.
Genes that code for proteins that regulate the CELL DIVISION CYCLE. These genes form a regulatory network that culminates in the onset of MITOSIS by activating the p34cdc2 protein (PROTEIN P34CDC2).
Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.
Established cell cultures that have the potential to propagate indefinitely.
A cyclin subtype that has specificity for CDC2 PROTEIN KINASE and CYCLIN-DEPENDENT KINASE 2. It plays a role in progression of the CELL CYCLE through G1/S and G2/M phase transitions.
The interval between two successive CELL DIVISIONS during which the CHROMOSOMES are not individually distinguishable. It is composed of the G phases (G1 PHASE; G0 PHASE; G2 PHASE) and S PHASE (when DNA replication occurs).
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
A cyclin subtype that is transported into the CELL NUCLEUS at the end of the G2 PHASE. It stimulates the G2/M phase transition by activating CDC2 PROTEIN KINASE.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
Cyclin-dependent kinase 4 is a key regulator of G1 PHASE of the CELL CYCLE. It partners with CYCLIN D to phosphorylate RETINOBLASTOMA PROTEIN. CDK4 activity is inhibited by CYCLIN-DEPENDENT KINASE INHIBITOR P16.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
Proteins that are normally involved in holding cellular growth in check. Deficiencies or abnormalities in these proteins may lead to unregulated cell growth and tumor development.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
A family of cell cycle-dependent kinases that are related in structure to CDC28 PROTEIN KINASE; S CEREVISIAE; and the CDC2 PROTEIN KINASE found in mammalian species.
The period of cyclic physiological and behavior changes in non-primate female mammals that exhibit ESTRUS. The estrous cycle generally consists of 4 or 5 distinct periods corresponding to the endocrine status (PROESTRUS; ESTRUS; METESTRUS; DIESTRUS; and ANESTRUS).
A subclass of dual specificity phosphatases that play a role in the progression of the CELL CYCLE. They dephosphorylate and activate CYCLIN-DEPENDENT KINASES.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.
A family of basic helix-loop-helix transcription factors that control expression of a variety of GENES involved in CELL CYCLE regulation. E2F transcription factors typically form heterodimeric complexes with TRANSCRIPTION FACTOR DP1 or transcription factor DP2, and they have N-terminal DNA binding and dimerization domains. E2F transcription factors can act as mediators of transcriptional repression or transcriptional activation.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
Elements of limited time intervals, contributing to particular results or situations.
A cyclin B subtype that colocalizes with MICROTUBULES during INTERPHASE and is transported into the CELL NUCLEUS at the end of the G2 PHASE.
A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
A cyclin subtype that is specific for CYCLIN-DEPENDENT KINASE 4 and CYCLIN-DEPENDENT KINASE 6. Unlike most cyclins, cyclin D expression is not cyclical, but rather it is expressed in response to proliferative signals. Cyclin D may therefore play a role in cellular responses to mitogenic signals.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
A series of oxidative reactions in the breakdown of acetyl units derived from GLUCOSE; FATTY ACIDS; or AMINO ACIDS by means of tricarboxylic acid intermediates. The end products are CARBON DIOXIDE, water, and energy in the form of phosphate bonds.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.
A nucleoside that substitutes for thymidine in DNA and thus acts as an antimetabolite. It causes breaks in chromosomes and has been proposed as an antiviral and antineoplastic agent. It has been given orphan drug status for use in the treatment of primary brain tumors.
An E2F transcription factor that interacts directly with RETINOBLASTOMA PROTEIN and CYCLIN A and activates GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis. E2F1 is involved in DNA REPAIR and APOPTOSIS.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Cell regulatory signaling system that controls progression through S PHASE and stabilizes the replication forks during conditions that could affect the fidelity of DNA REPLICATION, such as DNA DAMAGE or depletion of nucleotide pools.
A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.
A negative regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
A broadly expressed type D cyclin. Experiments using KNOCKOUT MICE suggest a role for cyclin D3 in LYMPHOCYTE development.
A group of cell cycle proteins that negatively regulate the activity of CYCLIN/CYCLIN-DEPENDENT KINASE complexes. They inhibit CELL CYCLE progression and help control CELL PROLIFERATION following GENOTOXIC STRESS as well as during CELL DIFFERENTIATION.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
Substances that inhibit or prevent the proliferation of NEOPLASMS.
Proteins found in any species of fungus.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
A genus of ascomycetous fungi of the family Schizosaccharomycetaceae, order Schizosaccharomycetales.
Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.
The cellular signaling system that halts the progression of cells through MITOSIS or MEIOSIS if a defect that will affect CHROMOSOME SEGREGATION is detected.
Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the replication fork during DNA replication. PCNA expression correlates with the proliferation activity of several malignant and non-malignant cell types.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in neoplastic tissue.
High molecular weight proteins found in the MICROTUBULES of the cytoskeletal system. Under certain conditions they are required for TUBULIN assembly into the microtubules and stabilize the assembled microtubules.
Products of proto-oncogenes. Normally they do not have oncogenic or transforming properties, but are involved in the regulation or differentiation of cell growth. They often have protein kinase activity.
The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.
An antineoplastic agent that inhibits DNA synthesis through the inhibition of ribonucleoside diphosphate reductase.
Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.
A product of the p16 tumor suppressor gene (GENES, P16). It is also called INK4 or INK4A because it is the prototype member of the INK4 CYCLIN-DEPENDENT KINASE INHIBITORS. This protein is produced from the alpha mRNA transcript of the p16 gene. The other gene product, produced from the alternatively spliced beta transcript, is TUMOR SUPPRESSOR PROTEIN P14ARF. Both p16 gene products have tumor suppressor functions.
A species of gram-negative, aerobic bacteria that consist of slender vibroid cells.
Cyclin-dependent kinase 6 associates with CYCLIN D and phosphorylates RETINOBLASTOMA PROTEIN during G1 PHASE of the CELL CYCLE. It helps regulate the transition to S PHASE and its kinase activity is inhibited by CYCLIN-DEPENDENT KINASE INHIBITOR P18.
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
A cyclin D subtype which is regulated by GATA4 TRANSCRIPTION FACTOR. Experiments using KNOCKOUT MICE suggest a role for cyclin D2 in granulosa cell proliferation and gonadal development.
A transcription factor that possesses DNA-binding and E2F-binding domains but lacks a transcriptional activation domain. It is a binding partner for E2F TRANSCRIPTION FACTORS and enhances the DNA binding and transactivation function of the DP-E2F complex.
3-Hydroxy-4-oxo-1(4H)-pyridinealanine. An antineoplastic alanine-substituted pyridine derivative isolated from Leucena glauca.
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
Complexes of enzymes that catalyze the covalent attachment of UBIQUITIN to other proteins by forming a peptide bond between the C-terminal GLYCINE of UBIQUITIN and the alpha-amino groups of LYSINE residues in the protein. The complexes play an important role in mediating the selective-degradation of short-lived and abnormal proteins. The complex of enzymes can be broken down into three components that involve activation of ubiquitin (UBIQUITIN-ACTIVATING ENZYMES), conjugation of ubiquitin to the ligase complex (UBIQUITIN-CONJUGATING ENZYMES), and ligation of ubiquitin to the substrate protein (UBIQUITIN-PROTEIN LIGASES).
Transport proteins that carry specific substances in the blood or across cell membranes.
A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
The rate dynamics in chemical or physical systems.
A ubiquitously expressed regulatory protein that contains a retinoblastoma protein binding domain and an AT-rich interactive domain. The protein may play a role in recruiting HISTONE DEACETYLASES to the site of RETINOBLASTOMA PROTEIN-containing transcriptional repressor complexes.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
A microtubule structure that forms during CELL DIVISION. It consists of two SPINDLE POLES, and sets of MICROTUBULES that may include the astral microtubules, the polar microtubules, and the kinetochore microtubules.
The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.
The continuous sequence of changes undergone by living organisms during the post-embryonic developmental process, such as metamorphosis in insects and amphibians. This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM.
An E3 ubiquitin ligase primarily involved in regulation of the metaphase-to-anaphase transition during MITOSIS through ubiquitination of specific CELL CYCLE PROTEINS. Enzyme activity is tightly regulated through subunits and cofactors, which modulate activation, inhibition, and substrate specificity. The anaphase-promoting complex, or APC-C, is also involved in tissue differentiation in the PLACENTA, CRYSTALLINE LENS, and SKELETAL MUSCLE, and in regulation of postmitotic NEURONAL PLASTICITY and excitability.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.
Proteins obtained from the species Schizosaccharomyces pombe. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
The cell center, consisting of a pair of CENTRIOLES surrounded by a cloud of amorphous material called the pericentriolar region. During interphase, the centrosome nucleates microtubule outgrowth. The centrosome duplicates and, during mitosis, separates to form the two poles of the mitotic spindle (MITOTIC SPINDLE APPARATUS).
Cellular DNA-binding proteins encoded by the c-myc genes. They are normally involved in nucleic acid metabolism and in mediating the cellular response to growth factors. Elevated and deregulated (constitutive) expression of c-myc proteins can cause tumorigenesis.
Nocodazole is an antineoplastic agent which exerts its effect by depolymerizing microtubules.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Cell lines whose original growing procedure consisted being transferred (T) every 3 days and plated at 300,000 cells per plate (J Cell Biol 17:299-313, 1963). Lines have been developed using several different strains of mice. Tissues are usually fibroblasts derived from mouse embryos but other types and sources have been developed as well. The 3T3 lines are valuable in vitro host systems for oncogenic virus transformation studies, since 3T3 cells possess a high sensitivity to CONTACT INHIBITION.
A widely-expressed cyclin A subtype that functions during the G1/S and G2/M transitions of the CELL CYCLE.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
A protein kinase encoded by the Saccharomyces cerevisiae CDC28 gene and required for progression from the G1 PHASE to the S PHASE in the CELL CYCLE.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in fungi.
A group of PROTEIN-SERINE-THREONINE KINASES which activate critical signaling cascades in double strand breaks, APOPTOSIS, and GENOTOXIC STRESS such as ionizing ultraviolet A light, thereby acting as a DNA damage sensor. These proteins play a role in a wide range of signaling mechanisms in cell cycle control.
Enzyme activated in response to DNA DAMAGE involved in cell cycle arrest. The gene is located on the long (q) arm of chromosome 22 at position 12.1. In humans it is encoded by the CHEK2 gene.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
A genus of gram-negative, aerobic, rod- or vibroid-shaped or fusiform bacteria that commonly produce a stalk. They are found in fresh water and soil and divide by binary transverse fission.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
The functional hereditary units of FUNGI.
The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.
A family of structurally-related proteins that were originally identified by their ability to complex with cyclin proteins (CYCLINS). They share a common domain that binds specifically to F-BOX MOTIFS. They take part in SKP CULLIN F-BOX PROTEIN LIGASES, where they can bind to a variety of F-BOX PROTEINS.
A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.
The decrease in the cell's ability to proliferate with the passing of time. Each cell is programmed for a certain number of cell divisions and at the end of that time proliferation halts. The cell enters a quiescent state after which it experiences CELL DEATH via the process of APOPTOSIS.
Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Thymidine is a pyrimidine nucleoside, consisting of a thymine base linked to a deoxyribose sugar by a β-N1-glycosidic bond, which plays a crucial role in DNA replication and repair processes as one of the four nucleosides in DNA.
Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.
An antiviral antibiotic produced by Cephalosporium aphidicola and other fungi. It inhibits the growth of eukaryotic cells and certain animal viruses by selectively inhibiting the cellular replication of DNA polymerase II or the viral-induced DNA polymerases. The drug may be useful for controlling excessive cell proliferation in patients with cancer, psoriasis or other dermatitis with little or no adverse effect upon non-multiplying cells.
Cell changes manifested by escape from control mechanisms, increased growth potential, alterations in the cell surface, karyotypic abnormalities, morphological and biochemical deviations from the norm, and other attributes conferring the ability to invade, metastasize, and kill.
A potent inhibitor of CYCLIN-DEPENDENT KINASES in G1 PHASE and S PHASE. In humans, aberrant expression of p57 is associated with various NEOPLASMS as well as with BECKWITH-WIEDEMANN SYNDROME.
Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
A negative regulator of the CELL CYCLE that undergoes PHOSPHORYLATION by CYCLIN-DEPENDENT KINASES. It contains a conserved pocket region that binds E2F4 TRANSCRIPTION FACTOR and interacts with viral ONCOPROTEINS such as POLYOMAVIRUS TUMOR ANTIGENS; ADENOVIRUS E1A PROTEINS; and PAPILLOMAVIRUS E7 PROTEINS.
New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.
Agents obtained from higher plants that have demonstrable cytostatic or antineoplastic activity.
Tumors or cancer of the human BREAST.
A negative regulator of the CELL CYCLE that undergoes PHOSPHORYLATION by CYCLIN-DEPENDENT KINASES. RBL2 contains a conserved pocket region that binds E2F4 TRANSCRIPTION FACTOR and E2F5 TRANSCRIPTION FACTOR. RBL2 also interacts with viral ONCOPROTEINS such as POLYOMAVIRUS TUMOR ANTIGENS; ADENOVIRUS E1A PROTEINS; and PAPILLOMAVIRUS E7 PROTEINS.
Membrane proteins encoded by the BCL-2 GENES and serving as potent inhibitors of cell death by APOPTOSIS. The proteins are found on mitochondrial, microsomal, and NUCLEAR MEMBRANE sites within many cell types. Overexpression of bcl-2 proteins, due to a translocation of the gene, is associated with follicular lymphoma.
A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.
Proteins and peptides that are involved in SIGNAL TRANSDUCTION within the cell. Included here are peptides and proteins that regulate the activity of TRANSCRIPTION FACTORS and cellular processes in response to signals from CELL SURFACE RECEPTORS. Intracellular signaling peptide and proteins may be part of an enzymatic signaling cascade or act through binding to and modifying the action of other signaling factors.
The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.
A cyclin subtype that is found associated with CYCLIN-DEPENDENT KINASE 5; cyclin G associated kinase, and PROTEIN PHOSPHATASE 2.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Endogenous or exogenous substances which inhibit the normal growth of human and animal cells or micro-organisms, as distinguished from those affecting plant growth (= PLANT GROWTH REGULATORS).
Tumor suppressor genes located on the short arm of human chromosome 17 and coding for the phosphoprotein p53.
That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Human COLORECTAL CARCINOMA cell line.
Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.
A large multisubunit complex that plays an important role in the degradation of most of the cytosolic and nuclear proteins in eukaryotic cells. It contains a 700-kDa catalytic sub-complex and two 700-kDa regulatory sub-complexes. The complex digests ubiquitinated proteins and protein activated via ornithine decarboxylase antizyme.
A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.
A furanyl adenine found in PLANTS and FUNGI. It has plant growth regulation effects.
Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
Proteins prepared by recombinant DNA technology.
Eukaryotic cell line obtained in a quiescent or stationary phase which undergoes conversion to a state of unregulated growth in culture, resembling an in vitro tumor. It occurs spontaneously or through interaction with viruses, oncogenes, radiation, or drugs/chemicals.
Processes that stimulate the GENETIC TRANSCRIPTION of a gene or set of genes.
A diverse class of enzymes that interact with UBIQUITIN-CONJUGATING ENZYMES and ubiquitination-specific protein substrates. Each member of this enzyme group has its own distinct specificity for a substrate and ubiquitin-conjugating enzyme. Ubiquitin-protein ligases exist as both monomeric proteins multiprotein complexes.
A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.
The artificial induction of GENE SILENCING by the use of RNA INTERFERENCE to reduce the expression of a specific gene. It includes the use of DOUBLE-STRANDED RNA, such as SMALL INTERFERING RNA and RNA containing HAIRPIN LOOP SEQUENCE, and ANTI-SENSE OLIGONUCLEOTIDES.
An E3 UBIQUITIN LIGASE that interacts with and inhibits TUMOR SUPPRESSOR PROTEIN P53. Its ability to ubiquitinate p53 is regulated by TUMOR SUPPRESSOR PROTEIN P14ARF.
Deoxyribonucleic acid that makes up the genetic material of fungi.
An E2F transcription factor that interacts directly with RETINOBLASTOMA PROTEIN and CYCLIN A. E2F2 activates GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.
The quantity of volume or surface area of CELLS.
Compounds that inhibit cell production of DNA or RNA.
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
Proteins coded by oncogenes. They include proteins resulting from the fusion of an oncogene and another gene (ONCOGENE PROTEINS, FUSION).
An expression of the number of mitoses found in a stated number of cells.
Nucleoproteins, which in contrast to HISTONES, are acid insoluble. They are involved in chromosomal functions; e.g. they bind selectively to DNA, stimulate transcription resulting in tissue-specific RNA synthesis and undergo specific changes in response to various hormones or phytomitogens.
Geminin inhibits DNA replication by preventing the incorporation of MCM complex into pre-replication complex. It is absent during G1 phase of the CELL CYCLE and accumulates through S, G2,and M phases. It is degraded at the metaphase-anaphase transition by the ANAPHASE-PROMOTING COMPLEX-CYCLOSOME.
Interruption or suppression of the expression of a gene at transcriptional or translational levels.
A CELL CYCLE and tumor growth marker which can be readily detected using IMMUNOCYTOCHEMISTRY methods. Ki-67 is a nuclear antigen present only in the nuclei of cycling cells.
Processes required for CELL ENLARGEMENT and CELL PROLIFERATION.
The phase of cell nucleus division following PROMETAPHASE, in which the CHROMOSOMES line up across the equatorial plane of the SPINDLE APPARATUS prior to separation.
Phosphoproteins are proteins that have been post-translationally modified with the addition of a phosphate group, usually on serine, threonine or tyrosine residues, which can play a role in their regulation, function, interaction with other molecules, and localization within the cell.
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
Mutant mice homozygous for the recessive gene "nude" which fail to develop a thymus. They are useful in tumor studies and studies on immune responses.
A cyclin A subtype primarily found in male GERM CELLS. It may play a role in the passage of SPERMATOCYTES into meiosis I.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
DNA present in neoplastic tissue.
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
Trans-acting proteins which accelerate retroviral virus replication. The vpr proteins act in trans to increase the levels of specified proteins. vpr is short for viral protein R, where R is undefined.
A cyclin G subtype that is constitutively expressed throughout the cell cycle. Cyclin G1 is considered a major transcriptional target of TUMOR SUPPRESSOR PROTEIN P53 and is highly induced in response to DNA damage.
A promyelocytic cell line derived from a patient with ACUTE PROMYELOCYTIC LEUKEMIA. HL-60 cells lack specific markers for LYMPHOID CELLS but express surface receptors for FC FRAGMENTS and COMPLEMENT SYSTEM PROTEINS. They also exhibit phagocytic activity and responsiveness to chemotactic stimuli. (From Hay et al., American Type Culture Collection, 7th ed, pp127-8)
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.

Drosophila oogenesis: versatile spn doctors. (1/24243)

Recent work on Drosophila oogenesis has uncovered connections between cell-cycle checkpoints and pattern formation. Genes of the spindle class, which encode double-strand break repair enzymes and RNA helicases, affect oocyte polarity and the decision whether to differentiate as an oocyte or a nurse cell.  (+info)

Transformation mediated by RhoA requires activity of ROCK kinases. (2/24243)

BACKGROUND: The Ras-related GTPase RhoA controls signalling processes required for cytoskeletal reorganisation, transcriptional regulation, and transformation. The ability of RhoA mutants to transform cells correlates not with transcription but with their ability to bind ROCK-I, an effector kinase involved in cytoskeletal reorganisation. We used a recently developed specific ROCK inhibitor, Y-27632, and ROCK truncation mutants to investigate the role of ROCK kinases in transcriptional activation and transformation. RESULTS: In NIH3T3 cells, Y-27632 did not prevent the activation of serum response factor, transcription of c-fos or cell cycle re-entry following serum stimulation. Repeated treatment of NIH3T3 cells with Y-27632, however, substantially disrupted their actin fibre network but did not affect their growth rate. Y-27632 blocked focus formation by RhoA and its guanine-nucleotide exchange factors Dbl and mNET1. It did not affect the growth rate of cells transformed by Dbl and mNET1, but restored normal growth control at confluence and prevented their growth in soft agar. Y-27632 also significantly inhibited focus formation by Ras, but had no effect on the establishment or maintenance of transformation by Src. Furthermore, it significantly inhibited anchorage-independent growth of two out of four colorectal tumour cell lines. Consistent with these data, a truncated ROCK derivative exhibited weak ability to cooperate with activated Raf in focus formation assays. CONCLUSIONS: ROCK signalling is required for both the establishment and maintenance of transformation by constitutive activation of RhoA, and contributes to the Ras-transformed phenotype. These observations provide a potential explanation for the requirement for Rho in Ras-mediated transformation. Moreover, the inhibition of ROCK kinases may be of therapeutic use.  (+info)

Difference between mammary epithelial cells from mature virgin and primiparous mice. (3/24243)

Mammary epithelial cells from mature virgin mice are similar to those from primiparous mice in several respects. However, there is one known difference. The cells from the mature virgin must traverse the cell cycle in order to become competent to make casein and enzymatically active alpha-lactalbumin in vitro; those from the primiparous animal can make these proteins without first traversing the cycle. In this regard, cells from human placental lactogen- and prolactin-treated mature virgins are, after involution, similar to those from primiparous mice. The developemental block in the cells from the mature virgin, imposed by preventing cell cycle traversal, has been partially delineated. It does not appear to reside at the levels of ultrastructural maturation or the formation of casein messenger RNA. Rather, the lesion is postranscriptional and may be at the level of translation, or posttranslational modification, or both.  (+info)

The role of RBF in the introduction of G1 regulation during Drosophila embryogenesis. (4/24243)

The first appearance of G1 during Drosophila embryogenesis, at cell cycle 17, is accompanied by the down-regulation of E2F-dependent transcription. Mutant alleles of rbf were generated and analyzed to determine the role of RBF in this process. Embryos lacking both maternal and zygotic RBF products show constitutive expression of PCNA and RNR2, two E2F-regulated genes, indicating that RBF is required for their transcriptional repression. Despite the ubiquitous expression of E2F target genes, most epidermal cells enter G1 normally. Rather than pausing in G1 until the appropriate time for cell cycle progression, many of these cells enter an ectopic S-phase. These results indicate that the repression of E2F target genes by RBF is necessary for the maintenance but not the initiation of a G1 phase. The phenotype of RBF-deficient embryos suggests that rbf has a function that is complementary to the roles of dacapo and fizzy-related in the introduction of G1 during Drosophila embryogenesis.  (+info)

Coupling of the cell cycle and myogenesis through the cyclin D1-dependent interaction of MyoD with cdk4. (5/24243)

Proliferating myoblasts express the muscle determination factor, MyoD, throughout the cell cycle in the absence of differentiation. Here we show that a mitogen-sensitive mechanism, involving the direct interaction between MyoD and cdk4, restricts myoblast differentiation to cells that have entered into the G0 phase of the cell cycle under mitogen withdrawal. Interaction between MyoD and cdk4 disrupts MyoD DNA-binding, muscle-specific gene activation and myogenic conversion of 10T1/2 cells independently of cyclin D1 and the CAK activation of cdk4. Forced induction of cyclin D1 in myotubes results in the cytoplasmic to nuclear translocation of cdk4. The specific MyoD-cdk4 interaction in dividing myoblasts, coupled with the cyclin D1-dependent nuclear targeting of cdk4, suggests a mitogen-sensitive mechanism whereby cyclin D1 can regulate MyoD function and the onset of myogenesis by controlling the cellular location of cdk4 rather than the phosphorylation status of MyoD.  (+info)

Ral-specific guanine nucleotide exchange factor activity opposes other Ras effectors in PC12 cells by inhibiting neurite outgrowth. (6/24243)

Ras proteins can activate at least three classes of downstream target proteins: Raf kinases, phosphatidylinositol-3 phosphate (PI3) kinase, and Ral-specific guanine nucleotide exchange factors (Ral-GEFs). In NIH 3T3 cells, activated Ral-GEFs contribute to Ras-induced cell proliferation and oncogenic transformation by complementing the activities of Raf and PI3 kinases. In PC12 cells, activated Raf and PI3 kinases mediate Ras-induced cell cycle arrest and differentiation into a neuronal phenotype. Here, we show that in PC12 cells, Ral-GEF activity acts opposite to other Ras effectors. Elevation of Ral-GEF activity induced by transfection of a mutant Ras protein that preferentially activates Ral-GEFs, or by transfection of the catalytic domain of the Ral-GEF Rgr, suppressed cell cycle arrest and neurite outgrowth induced by nerve growth factor (NGF) treatment. In addition, Rgr reduced neurite outgrowth induced by a mutant Ras protein that preferentially activates Raf kinases. Furthermore, inhibition of Ral-GEF activity by expression of a dominant negative Ral mutant accelerated cell cycle arrest and enhanced neurite outgrowth in response to NGF treatment. Ral-GEF activity may function, at least in part, through inhibition of the Rho family GTPases, CDC42 and Rac. In contrast to Ras, which was activated for hours by NGF treatment, Ral was activated for only approximately 20 min. These findings suggest that one function of Ral-GEF signaling induced by NGF is to delay the onset of cell cycle arrest and neurite outgrowth induced by other Ras effectors. They also demonstrate that Ras has the potential to promote both antidifferentiation and prodifferentiation signaling pathways through activation of distinct effector proteins. Thus, in some cell types the ratio of activities among Ras effectors and their temporal regulation may be important determinants for cell fate decisions between proliferation and differentiation.  (+info)

The abundance of cell cycle regulatory protein Cdc4p is controlled by interactions between its F box and Skp1p. (7/24243)

Posttranslational modification of a protein by ubiquitin usually results in rapid degradation of the ubiquitinated protein by the proteasome. The transfer of ubiquitin to substrate is a multistep process. Cdc4p is a component of a ubiquitin ligase that tethers the ubiquitin-conjugating enzyme Cdc34p to its substrates. Among the domains of Cdc4p that are crucial for function are the F-box, which links Cdc4p to Cdc53p through Skp1p, and the WD-40 repeats, which are required for binding the substrate for Cdc34p. In addition to Cdc4p, other F-box proteins, including Grr1p and Met30p, may similarly act together with Cdc53p and Skp1p to function as ubiquitin ligase complexes. Because the relative abundance of these complexes, known collectively as SCFs, is important for cell viability, we have sought evidence of mechanisms that modulate F-box protein regulation. Here we demonstrate that the abundance of Cdc4p is subject to control by a peptide segment that we term the R-motif (for "reduced abundance"). Furthermore, we show that binding of Skp1p to the F-box of Cdc4p inhibits R-motif-dependent degradation of Cdc4p. These results suggest a general model for control of SCF activities.  (+info)

Induced expression of p16(INK4a) inhibits both CDK4- and CDK2-associated kinase activity by reassortment of cyclin-CDK-inhibitor complexes. (8/24243)

To investigate the mode of action of the p16(INK4a) tumor suppressor protein, we have established U2-OS cells in which the expression of p16(INK4a) can be regulated by addition or removal of isopropyl-beta-D-thiogalactopyranoside. As expected, induction of p16(INK4a) results in a G1 cell cycle arrest by inhibiting phosphorylation of the retinoblastoma protein (pRb) by the cyclin-dependent kinases CDK4 and CDK6. However, induction of p16(INK4a) also causes marked inhibition of CDK2 activity. In the case of cyclin E-CDK2, this is brought about by reassortment of cyclin, CDK, and CDK-inhibitor complexes, particularly those involving p27(KIP1). Size fractionation of the cellular lysates reveals that a substantial proportion of CDK4 participates in active kinase complexes of around 200 kDa. Upon induction of p16(INK4a), this complex is partly dissociated, and the majority of CDK4 is found in lower-molecular-weight fractions consistent with the formation of a binary complex with p16(INK4a). Sequestration of CDK4 by p16(INK4a) allows cyclin D1 to associate increasingly with CDK2, without affecting its interactions with the CIP/KIP inhibitors. Thus, upon the induction of p16(INK4a), p27(KIP1) appears to switch its allegiance from CDK4 to CDK2, and the accompanying reassortment of components leads to the inhibition of cyclin E-CDK2 by p27(KIP1) and p21(CIP1). Significantly, p16(INK4a) itself does not appear to form higher-order complexes, and the overwhelming majority remains either free or forms binary associations with CDK4 and CDK6.  (+info)

The cell cycle is a series of events that take place in a cell leading to its division and duplication. It consists of four main phases: G1 phase, S phase, G2 phase, and M phase.

During the G1 phase, the cell grows in size and synthesizes mRNA and proteins in preparation for DNA replication. In the S phase, the cell's DNA is copied, resulting in two complete sets of chromosomes. During the G2 phase, the cell continues to grow and produces more proteins and organelles necessary for cell division.

The M phase is the final stage of the cell cycle and consists of mitosis (nuclear division) and cytokinesis (cytoplasmic division). Mitosis results in two genetically identical daughter nuclei, while cytokinesis divides the cytoplasm and creates two separate daughter cells.

The cell cycle is regulated by various checkpoints that ensure the proper completion of each phase before progressing to the next. These checkpoints help prevent errors in DNA replication and division, which can lead to mutations and cancer.

Cell cycle proteins are a group of regulatory proteins that control the progression of the cell cycle, which is the series of events that take place in a eukaryotic cell leading to its division and duplication. These proteins can be classified into several categories based on their functions during different stages of the cell cycle.

The major groups of cell cycle proteins include:

1. Cyclin-dependent kinases (CDKs): CDKs are serine/threonine protein kinases that regulate key transitions in the cell cycle. They require binding to a regulatory subunit called cyclin to become active. Different CDK-cyclin complexes are activated at different stages of the cell cycle.
2. Cyclins: Cyclins are a family of regulatory proteins that bind and activate CDKs. Their levels fluctuate throughout the cell cycle, with specific cyclins expressed during particular phases. For example, cyclin D is important for the G1 to S phase transition, while cyclin B is required for the G2 to M phase transition.
3. CDK inhibitors (CKIs): CKIs are regulatory proteins that bind to and inhibit CDKs, thereby preventing their activation. CKIs can be divided into two main families: the INK4 family and the Cip/Kip family. INK4 family members specifically inhibit CDK4 and CDK6, while Cip/Kip family members inhibit a broader range of CDKs.
4. Anaphase-promoting complex/cyclosome (APC/C): APC/C is an E3 ubiquitin ligase that targets specific proteins for degradation by the 26S proteasome. During the cell cycle, APC/C regulates the metaphase to anaphase transition and the exit from mitosis by targeting securin and cyclin B for degradation.
5. Other regulatory proteins: Several other proteins play crucial roles in regulating the cell cycle, such as p53, a transcription factor that responds to DNA damage and arrests the cell cycle, and the polo-like kinases (PLKs), which are involved in various aspects of mitosis.

Overall, cell cycle proteins work together to ensure the proper progression of the cell cycle, maintain genomic stability, and prevent uncontrolled cell growth, which can lead to cancer.

Cell cycle checkpoints are control mechanisms that regulate the cell cycle and ensure the accurate and timely progression through different phases of the cell cycle. These checkpoints monitor specific cellular events, such as DNA replication and damage, chromosome separation, and proper attachment of the mitotic spindle to the chromosomes. If any of these events fail to occur properly or are delayed, the cell cycle checkpoints trigger a response that can halt the cell cycle until the problem is resolved. This helps to prevent cells with damaged or incomplete genomes from dividing and potentially becoming cancerous.

There are three main types of cell cycle checkpoints:

1. G1 Checkpoint: Also known as the restriction point, this checkpoint controls the transition from the G1 phase to the S phase of the cell cycle. It monitors the availability of nutrients, growth factors, and the integrity of the genome before allowing the cell to proceed into DNA replication.
2. G2 Checkpoint: This checkpoint regulates the transition from the G2 phase to the M phase of the cell cycle. It checks for completion of DNA replication and absence of DNA damage before allowing the cell to enter mitosis.
3. Mitotic (M) Checkpoint: Also known as the spindle assembly checkpoint, this checkpoint ensures that all chromosomes are properly attached to the mitotic spindle before anaphase begins. It prevents the separation of sister chromatids until all kinetochores are correctly attached and tension is established between them.

Cell cycle checkpoints play a crucial role in maintaining genomic stability, preventing tumorigenesis, and ensuring proper cell division. Dysregulation of these checkpoints can lead to various diseases, including cancer.

The G1 phase, or Gap 1 phase, is the first phase of the cell cycle, during which the cell grows in size and synthesizes mRNA and proteins in preparation for subsequent steps leading to mitosis. During this phase, the cell also checks its growth and makes sure that it is large enough to proceed through the cell cycle. If the cell is not large enough, it will arrest in the G1 phase until it has grown sufficiently. The G1 phase is followed by the S phase, during which DNA replication occurs.

In the context of cell biology, "S phase" refers to the part of the cell cycle during which DNA replication occurs. The "S" stands for synthesis, reflecting the active DNA synthesis that takes place during this phase. It is preceded by G1 phase (gap 1) and followed by G2 phase (gap 2), with mitosis (M phase) being the final stage of the cell cycle.

During S phase, the cell's DNA content effectively doubles as each chromosome is replicated to ensure that the two resulting daughter cells will have the same genetic material as the parent cell. This process is carefully regulated and coordinated with other events in the cell cycle to maintain genomic stability.

Mitosis is a type of cell division in which the genetic material of a single cell, called the mother cell, is equally distributed into two identical daughter cells. It's a fundamental process that occurs in multicellular organisms for growth, maintenance, and repair, as well as in unicellular organisms for reproduction.

The process of mitosis can be broken down into several stages: prophase, prometaphase, metaphase, anaphase, and telophase. During prophase, the chromosomes condense and become visible, and the nuclear envelope breaks down. In prometaphase, the nuclear membrane is completely disassembled, and the mitotic spindle fibers attach to the chromosomes at their centromeres.

During metaphase, the chromosomes align at the metaphase plate, an imaginary line equidistant from the two spindle poles. In anaphase, sister chromatids are pulled apart by the spindle fibers and move toward opposite poles of the cell. Finally, in telophase, new nuclear envelopes form around each set of chromosomes, and the chromosomes decondense and become less visible.

Mitosis is followed by cytokinesis, a process that divides the cytoplasm of the mother cell into two separate daughter cells. The result of mitosis and cytokinesis is two genetically identical cells, each with the same number and kind of chromosomes as the original parent cell.

Cyclins are a family of regulatory proteins that play a crucial role in the cell cycle, which is the series of events that take place as a cell grows, divides, and produces two daughter cells. They are called cyclins because their levels fluctuate or cycle during the different stages of the cell cycle.

Cyclins function as subunits of serine/threonine protein kinase complexes, forming an active enzyme that adds phosphate groups to other proteins, thereby modifying their activity. This post-translational modification is a critical mechanism for controlling various cellular processes, including the regulation of the cell cycle.

There are several types of cyclins (A, B, D, and E), each of which is active during specific phases of the cell cycle:

1. Cyclin D: Expressed in the G1 phase, it helps to initiate the cell cycle by activating cyclin-dependent kinases (CDKs) that promote progression through the G1 restriction point.
2. Cyclin E: Active during late G1 and early S phases, it forms a complex with CDK2 to regulate the transition from G1 to S phase, where DNA replication occurs.
3. Cyclin A: Expressed in the S and G2 phases, it associates with both CDK2 and CDK1 to control the progression through the S and G2 phases and entry into mitosis (M phase).
4. Cyclin B: Active during late G2 and M phases, it partners with CDK1 to regulate the onset of mitosis by controlling the breakdown of the nuclear envelope, chromosome condensation, and spindle formation.

The activity of cyclins is tightly controlled through several mechanisms, including transcriptional regulation, protein degradation, and phosphorylation/dephosphorylation events. Dysregulation of cyclin expression or function can lead to uncontrolled cell growth and proliferation, which are hallmarks of cancer.

Cell division is the process by which a single eukaryotic cell (a cell with a true nucleus) divides into two identical daughter cells. This complex process involves several stages, including replication of DNA, separation of chromosomes, and division of the cytoplasm. There are two main types of cell division: mitosis and meiosis.

Mitosis is the type of cell division that results in two genetically identical daughter cells. It is a fundamental process for growth, development, and tissue repair in multicellular organisms. The stages of mitosis include prophase, prometaphase, metaphase, anaphase, and telophase, followed by cytokinesis, which divides the cytoplasm.

Meiosis, on the other hand, is a type of cell division that occurs in the gonads (ovaries and testes) during the production of gametes (sex cells). Meiosis results in four genetically unique daughter cells, each with half the number of chromosomes as the parent cell. This process is essential for sexual reproduction and genetic diversity. The stages of meiosis include meiosis I and meiosis II, which are further divided into prophase, prometaphase, metaphase, anaphase, and telophase.

In summary, cell division is the process by which a single cell divides into two daughter cells, either through mitosis or meiosis. This process is critical for growth, development, tissue repair, and sexual reproduction in multicellular organisms.

The menstrual cycle is a series of natural changes that occur in the female reproductive system over an approximate 28-day interval, marking the body's preparation for potential pregnancy. It involves the interplay of hormones that regulate the growth and disintegration of the uterine lining (endometrium) and the release of an egg (ovulation) from the ovaries.

The menstrual cycle can be divided into three main phases:

1. Menstrual phase: The cycle begins with the onset of menstruation, where the thickened uterine lining is shed through the vagina, lasting typically for 3-7 days. This shedding occurs due to a decrease in estrogen and progesterone levels, which are hormones essential for maintaining the endometrium during the previous cycle.

2. Follicular phase: After menstruation, the follicular phase commences with the pituitary gland releasing follicle-stimulating hormone (FSH). FSH stimulates the growth of several ovarian follicles, each containing an immature egg. One dominant follicle usually becomes selected to mature and release an egg during ovulation. Estrogen levels rise as the dominant follicle grows, causing the endometrium to thicken in preparation for a potential pregnancy.

3. Luteal phase: Following ovulation, the ruptured follicle transforms into the corpus luteum, which produces progesterone and estrogen to further support the endometrial thickening. If fertilization does not occur within approximately 24 hours after ovulation, the corpus luteum will degenerate, leading to a decline in hormone levels. This drop triggers the onset of menstruation, initiating a new menstrual cycle.

Understanding the menstrual cycle is crucial for monitoring reproductive health and planning or preventing pregnancies. Variations in cycle length and symptoms are common among women, but persistent irregularities may indicate underlying medical conditions requiring further evaluation by a healthcare professional.

The G2 phase, also known as the "gap 2 phase," is a stage in the cell cycle that occurs after DNA replication (S phase) and before cell division (mitosis). During this phase, the cell prepares for mitosis by completing the synthesis of proteins and organelles needed for chromosome separation. The cell also checks for any errors or damage to the DNA before entering mitosis. This phase is a critical point in the cell cycle where proper regulation ensures the faithful transmission of genetic information from one generation of cells to the next. If significant DNA damage is detected during G2, the cell may undergo programmed cell death (apoptosis) instead of dividing.

Cyclin-dependent kinase inhibitor p21, also known as CDKN1A or p21/WAF1/CIP1, is a protein that regulates the cell cycle. It inhibits the activity of cyclin-dependent kinases (CDKs), which are enzymes that play crucial roles in controlling the progression of the cell cycle.

The binding of p21 to CDKs prevents the phosphorylation and activation of downstream targets, leading to cell cycle arrest. This protein is transcriptionally activated by tumor suppressor protein p53 in response to DNA damage or other stress signals, and it functions as an important mediator of p53-dependent growth arrest.

By inhibiting CDKs, p21 helps to ensure that cells do not proceed through the cell cycle until damaged DNA has been repaired, thereby preventing the propagation of potentially harmful mutations. Additionally, p21 has been implicated in other cellular processes such as apoptosis, differentiation, and senescence. Dysregulation of p21 has been associated with various human diseases, including cancer.

Apoptosis is a programmed and controlled cell death process that occurs in multicellular organisms. It is a natural process that helps maintain tissue homeostasis by eliminating damaged, infected, or unwanted cells. During apoptosis, the cell undergoes a series of morphological changes, including cell shrinkage, chromatin condensation, and fragmentation into membrane-bound vesicles called apoptotic bodies. These bodies are then recognized and engulfed by neighboring cells or phagocytic cells, preventing an inflammatory response. Apoptosis is regulated by a complex network of intracellular signaling pathways that involve proteins such as caspases, Bcl-2 family members, and inhibitors of apoptosis (IAPs).

Cyclin-Dependent Kinase Inhibitor p27, also known as CDKN1B or p27Kip1, is a protein that regulates the cell cycle. It inhibits the activity of certain cyclin-dependent kinases (CDKs), which are enzymes that play key roles in regulating the progression of the cell cycle.

The cell cycle is a series of events that cells undergo as they grow and divide. Cyclins and CDKs help to control the different stages of the cell cycle by activating and deactivating various proteins at specific times. The p27 protein acts as a brake on the cell cycle, preventing cells from dividing too quickly or abnormally.

When p27 binds to a CDK-cyclin complex, it prevents the complex from phosphorylating its target proteins, which are necessary for the progression of the cell cycle. By inhibiting CDK activity, p27 helps to ensure that cells divide only when the proper conditions are met.

Mutations in the CDKN1B gene, which encodes p27, have been associated with several types of cancer, including breast, lung, and prostate cancer. These mutations can lead to decreased levels of p27 or impaired function, allowing cells to divide uncontrollably and form tumors.

Retinoblastoma Protein (pRb or RB1) is a tumor suppressor protein that plays a critical role in regulating the cell cycle and preventing uncontrolled cell growth. It is encoded by the RB1 gene, located on chromosome 13. The retinoblastoma protein functions as a regulatory checkpoint in the cell cycle, preventing cells from progressing into the S phase (DNA synthesis phase) until certain conditions are met.

When pRb is in its active state, it binds to and inhibits the activity of E2F transcription factors, which promote the expression of genes required for DNA replication and cell cycle progression. Phosphorylation of pRb by cyclin-dependent kinases (CDKs) leads to the release of E2F factors, allowing them to activate their target genes and drive the cell into S phase.

Mutations in the RB1 gene can result in the production of a nonfunctional or reduced amount of pRb protein, leading to uncontrolled cell growth and an increased risk of developing retinoblastoma, a rare form of eye cancer, as well as other types of tumors.

Cell proliferation is the process by which cells increase in number, typically through the process of cell division. In the context of biology and medicine, it refers to the reproduction of cells that makes up living tissue, allowing growth, maintenance, and repair. It involves several stages including the transition from a phase of quiescence (G0 phase) to an active phase (G1 phase), DNA replication in the S phase, and mitosis or M phase, where the cell divides into two daughter cells.

Abnormal or uncontrolled cell proliferation is a characteristic feature of many diseases, including cancer, where deregulated cell cycle control leads to excessive and unregulated growth of cells, forming tumors that can invade surrounding tissues and metastasize to distant sites in the body.

The G2 phase cell cycle checkpoint is a point in the cell cycle, specifically in the G2 phase, where the cell checks for any DNA damage or other issues that may have occurred during the DNA synthesis phase (S phase) before proceeding to mitosis. This checkpoint serves as a quality control mechanism to ensure that the genetic material is accurately and completely replicated and that the cell is ready to divide. If DNA damage or other problems are detected, the cell cycle is halted at the G2 checkpoint until the issues can be resolved. If the damage is too severe or cannot be repaired, the cell may undergo programmed cell death (apoptosis) to prevent the propagation of potentially harmful mutations.

G0 phase, also known as the resting phase or quiescent stage, is a part of the cell cycle in which cells are not actively preparing to divide. In this phase, cells are metabolically active and can carry out their normal functions, but they are not synthesizing DNA or dividing. Cells in G0 phase have left the cell cycle and may remain in this phase for an indefinite period of time, until they receive signals to re-enter the cell cycle and begin preparing for division again.

It's important to note that not all cells go through the G0 phase. Some cells, such as stem cells and certain types of immune cells, may spend most of their time in G0 phase and only enter the cell cycle when they are needed to replace damaged or dying cells. Other cells, such as those lining the digestive tract, continuously divide and do not have a G0 phase.

CDC2 protein kinase, also known as cell division cycle 2 or CDK1, is a type of enzyme that plays a crucial role in the regulation of the cell cycle. The cell cycle is the series of events that cells undergo as they grow, replicate their DNA, and divide into two daughter cells.

CDC2 protein kinase is a member of the cyclin-dependent kinase (CDK) family, which are serine/threonine protein kinases that are activated by binding to regulatory subunits called cyclins. CDC2 protein kinase is primarily associated with the regulation of the G2 phase and the entry into mitosis, the stage of the cell cycle where nuclear and cytoplasmic division occur.

CDC2 protein kinase functions by phosphorylating various target proteins, which alters their activity and contributes to the coordination of the different events that occur during the cell cycle. The activity of CDC2 protein kinase is tightly regulated through a variety of mechanisms, including phosphorylation and dephosphorylation, as well as the binding and destruction of cyclin subunits.

Dysregulation of CDC2 protein kinase has been implicated in various human diseases, including cancer, where uncontrolled cell division can lead to the formation of tumors. Therefore, understanding the regulation and function of CDC2 protein kinase is an important area of research in molecular biology and medicine.

A cell line that is derived from tumor cells and has been adapted to grow in culture. These cell lines are often used in research to study the characteristics of cancer cells, including their growth patterns, genetic changes, and responses to various treatments. They can be established from many different types of tumors, such as carcinomas, sarcomas, and leukemias. Once established, these cell lines can be grown and maintained indefinitely in the laboratory, allowing researchers to conduct experiments and studies that would not be feasible using primary tumor cells. It is important to note that tumor cell lines may not always accurately represent the behavior of the original tumor, as they can undergo genetic changes during their time in culture.

The G1 phase cell cycle checkpoint is a point in the cell cycle where the cell checks and regulates its progression from the G1 phase to the S phase. During this checkpoint, the cell evaluates various factors such as availability of nutrients, growth factors, and the absence of DNA damage to determine whether it should proceed with DNA replication or undergo cellular senescence, differentiation, or apoptosis (programmed cell death). The G1 phase checkpoint is controlled by a complex network of signaling pathways, including the p53 and Rb tumor suppressor proteins.

Tumor suppressor protein p53, also known as p53 or tumor protein p53, is a nuclear phosphoprotein that plays a crucial role in preventing cancer development and maintaining genomic stability. It does so by regulating the cell cycle and acting as a transcription factor for various genes involved in apoptosis (programmed cell death), DNA repair, and cell senescence (permanent cell growth arrest).

In response to cellular stress, such as DNA damage or oncogene activation, p53 becomes activated and accumulates in the nucleus. Activated p53 can then bind to specific DNA sequences and promote the transcription of target genes that help prevent the proliferation of potentially cancerous cells. These targets include genes involved in cell cycle arrest (e.g., CDKN1A/p21), apoptosis (e.g., BAX, PUMA), and DNA repair (e.g., GADD45).

Mutations in the TP53 gene, which encodes p53, are among the most common genetic alterations found in human cancers. These mutations often lead to a loss or reduction of p53's tumor suppressive functions, allowing cancer cells to proliferate uncontrollably and evade apoptosis. As a result, p53 has been referred to as "the guardian of the genome" due to its essential role in preventing tumorigenesis.

Cyclin-Dependent Kinase 2 (CDK2) is a type of enzyme that plays a crucial role in the regulation of the cell cycle, which is the process by which cells grow and divide. CDK2 is activated when it binds to a regulatory subunit called a cyclin.

During the cell cycle, CDK2 helps to control the progression from the G1 phase to the S phase, where DNA replication occurs. Specifically, CDK2 phosphorylates various target proteins that are involved in the regulation of DNA replication and the initiation of mitosis, which is the process of cell division.

CDK2 activity is tightly regulated through a variety of mechanisms, including phosphorylation, dephosphorylation, and protein degradation. Dysregulation of CDK2 activity has been implicated in various human diseases, including cancer. Therefore, CDK2 is an important target for the development of therapies aimed at treating these diseases.

Protein-Serine-Threonine Kinases (PSTKs) are a type of protein kinase that catalyzes the transfer of a phosphate group from ATP to the hydroxyl side chains of serine or threonine residues on target proteins. This phosphorylation process plays a crucial role in various cellular signaling pathways, including regulation of metabolism, gene expression, cell cycle progression, and apoptosis. PSTKs are involved in many physiological and pathological processes, and their dysregulation has been implicated in several diseases, such as cancer, diabetes, and neurodegenerative disorders.

Cyclin D1 is a type of cyclin protein that plays a crucial role in the regulation of the cell cycle, which is the process by which cells divide and grow. Specifically, Cyclin D1 is involved in the transition from the G1 phase to the S phase of the cell cycle. It does this by forming a complex with and acting as a regulatory subunit of cyclin-dependent kinase 4 (CDK4) or CDK6, which phosphorylates and inactivates the retinoblastoma protein (pRb). This allows the E2F transcription factors to be released and activate the transcription of genes required for DNA replication and cell cycle progression.

Overexpression of Cyclin D1 has been implicated in the development of various types of cancer, as it can lead to uncontrolled cell growth and division. Therefore, Cyclin D1 is an important target for cancer therapy, and inhibitors of CDK4/6 have been developed to treat certain types of cancer that overexpress Cyclin D1.

Phosphorylation is the process of adding a phosphate group (a molecule consisting of one phosphorus atom and four oxygen atoms) to a protein or other organic molecule, which is usually done by enzymes called kinases. This post-translational modification can change the function, localization, or activity of the target molecule, playing a crucial role in various cellular processes such as signal transduction, metabolism, and regulation of gene expression. Phosphorylation is reversible, and the removal of the phosphate group is facilitated by enzymes called phosphatases.

DNA replication is the biological process by which DNA makes an identical copy of itself during cell division. It is a fundamental mechanism that allows genetic information to be passed down from one generation of cells to the next. During DNA replication, each strand of the double helix serves as a template for the synthesis of a new complementary strand. This results in the creation of two identical DNA molecules. The enzymes responsible for DNA replication include helicase, which unwinds the double helix, and polymerase, which adds nucleotides to the growing strands.

Cyclin E is a type of cyclin protein that plays a crucial role in the regulation of the cell cycle, particularly during the G1 phase and the transition to the S phase. It functions as a regulatory subunit of the Cyclin-dependent kinase 2 (CDK2) complex, which is responsible for promoting the progression of the cell cycle.

Cyclin E is synthesized during the late G1 phase of the cell cycle and accumulates to high levels until it forms a complex with CDK2. The Cyclin E-CDK2 complex then phosphorylates several target proteins, leading to the activation of various downstream pathways that promote DNA replication and cell cycle progression.

The regulation of Cyclin E expression and activity is tightly controlled through multiple mechanisms, including transcriptional regulation, protein stability, and proteasomal degradation. Dysregulation of Cyclin E has been implicated in various human cancers, including breast, ovarian, and lung cancer, due to its role in promoting uncontrolled cell proliferation and genomic instability.

I'm happy to help! However, I believe there may be a slight mistake in your question. The abbreviation "cdc" is not typically associated with genetics or genes in the context of medical definitions.

If you meant to ask for a definition of "genes," here it is:

Genes are segments of DNA (deoxyribonucleic acid) that contain the instructions for the development, function, and reproduction of all living organisms. They are the basic units of heredity, passed down from one generation to the next. Genes encode specific proteins or RNA molecules that play critical roles in the structure, function, and regulation of the body's cells, tissues, and organs.

If you had a different term in mind, please let me know, and I will be happy to provide a definition for it!

DNA damage refers to any alteration in the structure or composition of deoxyribonucleic acid (DNA), which is the genetic material present in cells. DNA damage can result from various internal and external factors, including environmental exposures such as ultraviolet radiation, tobacco smoke, and certain chemicals, as well as normal cellular processes such as replication and oxidative metabolism.

Examples of DNA damage include base modifications, base deletions or insertions, single-strand breaks, double-strand breaks, and crosslinks between the two strands of the DNA helix. These types of damage can lead to mutations, genomic instability, and chromosomal aberrations, which can contribute to the development of diseases such as cancer, neurodegenerative disorders, and aging-related conditions.

The body has several mechanisms for repairing DNA damage, including base excision repair, nucleotide excision repair, mismatch repair, and double-strand break repair. However, if the damage is too extensive or the repair mechanisms are impaired, the cell may undergo apoptosis (programmed cell death) to prevent the propagation of potentially harmful mutations.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

Cyclin A is a type of cyclin protein that regulates the progression of the cell cycle, particularly through the G1 and S phases. It forms a complex with and acts as a regulatory subunit for cyclin-dependent kinases (CDKs), specifically CDK2 and CDK1. The activation of Cyclin A-CDK complexes leads to phosphorylation of various target proteins, which in turn regulates DNA replication and the transition to mitosis.

Cyclin A levels rise during the late G1 phase and peak during the S phase, after which they decline rapidly during the G2 phase. Any abnormalities in Cyclin A regulation or expression can contribute to uncontrolled cell growth and cancer development.

Interphase is a phase in the cell cycle during which the cell primarily performs its functions of growth and DNA replication. It is the longest phase of the cell cycle, consisting of G1 phase (during which the cell grows and prepares for DNA replication), S phase (during which DNA replication occurs), and G2 phase (during which the cell grows further and prepares for mitosis). During interphase, the chromosomes are in their relaxed, extended form and are not visible under the microscope. Interphase is followed by mitosis, during which the chromosomes condense and separate to form two genetically identical daughter cells.

DNA-binding proteins are a type of protein that have the ability to bind to DNA (deoxyribonucleic acid), the genetic material of organisms. These proteins play crucial roles in various biological processes, such as regulation of gene expression, DNA replication, repair and recombination.

The binding of DNA-binding proteins to specific DNA sequences is mediated by non-covalent interactions, including electrostatic, hydrogen bonding, and van der Waals forces. The specificity of binding is determined by the recognition of particular nucleotide sequences or structural features of the DNA molecule.

DNA-binding proteins can be classified into several categories based on their structure and function, such as transcription factors, histones, and restriction enzymes. Transcription factors are a major class of DNA-binding proteins that regulate gene expression by binding to specific DNA sequences in the promoter region of genes and recruiting other proteins to modulate transcription. Histones are DNA-binding proteins that package DNA into nucleosomes, the basic unit of chromatin structure. Restriction enzymes are DNA-binding proteins that recognize and cleave specific DNA sequences, and are widely used in molecular biology research and biotechnology applications.

Cyclin B is a type of cyclin protein that regulates the cell cycle, specifically the transition from G2 phase to mitosis (M phase) in eukaryotic cells. Cyclin B binds and activates cyclin-dependent kinase 1 (CDK1), forming the complex known as M-phase promoting factor (MPF). This complex triggers the events leading to cell division, such as chromosome condensation, nuclear envelope breakdown, and spindle formation. The levels of cyclin B increase during the G2 phase and are degraded by the anaphase-promoting complex/cyclosome (APC/C) at the onset of anaphase, allowing the cell cycle to progress into the next phase.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Flow cytometry is a medical and research technique used to measure physical and chemical characteristics of cells or particles, one cell at a time, as they flow in a fluid stream through a beam of light. The properties measured include:

* Cell size (light scatter)
* Cell internal complexity (granularity, also light scatter)
* Presence or absence of specific proteins or other molecules on the cell surface or inside the cell (using fluorescent antibodies or other fluorescent probes)

The technique is widely used in cell counting, cell sorting, protein engineering, biomarker discovery and monitoring disease progression, particularly in hematology, immunology, and cancer research.

Cyclin-Dependent Kinase 4 (CDK4) is a type of enzyme, specifically a serine/threonine protein kinase, that plays a crucial role in the regulation of the cell cycle. The cell cycle is the series of events that take place in a cell leading to its division and duplication. CDK4, when activated by binding to cyclin D, helps to promote the transition from the G1 phase to the S phase of the cell cycle. This transition is a critical point in the regulation of cell growth and division, and dysregulation of this process can lead to uncontrolled cell growth and cancer. CDK4 inhibitors are used in the treatment of certain types of cancer, such as breast and lung cancer, to block the activity of CDK4 and prevent tumor cell proliferation.

Nuclear proteins are a category of proteins that are primarily found in the nucleus of a eukaryotic cell. They play crucial roles in various nuclear functions, such as DNA replication, transcription, repair, and RNA processing. This group includes structural proteins like lamins, which form the nuclear lamina, and regulatory proteins, such as histones and transcription factors, that are involved in gene expression. Nuclear localization signals (NLS) often help target these proteins to the nucleus by interacting with importin proteins during active transport across the nuclear membrane.

Tumor suppressor proteins are a type of regulatory protein that helps control the cell cycle and prevent cells from dividing and growing in an uncontrolled manner. They work to inhibit tumor growth by preventing the formation of tumors or slowing down their progression. These proteins can repair damaged DNA, regulate gene expression, and initiate programmed cell death (apoptosis) if the damage is too severe for repair.

Mutations in tumor suppressor genes, which provide the code for these proteins, can lead to a decrease or loss of function in the resulting protein. This can result in uncontrolled cell growth and division, leading to the formation of tumors and cancer. Examples of tumor suppressor proteins include p53, Rb (retinoblastoma), and BRCA1/2.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

CDC2 and CDC28 are members of the Serine/Threonine protein kinase family, which play crucial roles in the regulation of the cell cycle. These kinases were originally identified in yeast (CDC28) and humans (CDC2), but they are highly conserved across eukaryotes.

CDC2-CDC28 Kinases function as a part of larger complexes, often associated with cyclins, to control different phases of the cell cycle by phosphorylating specific substrates at key regulatory points. The activity of CDC2-CDC28 Kinases is tightly regulated through various mechanisms, including phosphorylation, dephosphorylation, and protein binding interactions.

During the G2 phase of the cell cycle, CDC2-CDC28 Kinases are inactivated by phosphorylation at specific residues (Tyr15 and Thr14). As the cell approaches mitosis, a family of phosphatases called Cdc25 removes these inhibitory phosphates, leading to activation of the kinase. Activated CDC2-CDC28 Kinases then initiate mitotic processes such as chromosome condensation and nuclear envelope breakdown.

In summary, CDC2-CDC28 Kinases are essential regulators of the eukaryotic cell cycle, controlling various aspects of cell division through phosphorylation of specific substrates. Their activity is tightly regulated to ensure proper progression through the cell cycle and prevent uncontrolled cell growth, which can lead to diseases such as cancer.

The estrous cycle is the reproductive cycle in certain mammals, characterized by regular changes in the reproductive tract and behavior, which are regulated by hormonal fluctuations. It is most commonly observed in non-primate mammals such as dogs, cats, cows, pigs, and horses.

The estrous cycle consists of several stages:

1. Proestrus: This stage lasts for a few days and is characterized by the development of follicles in the ovaries and an increase in estrogen levels. During this time, the female may show signs of sexual receptivity, but will not allow mating to occur.
2. Estrus: This is the period of sexual receptivity, during which the female allows mating to take place. It typically lasts for a few days and is marked by a surge in luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which triggers ovulation.
3. Metestrus: This stage follows ovulation and is characterized by the formation of a corpus luteum, a structure that produces progesterone to support pregnancy. If fertilization does not occur, the corpus luteum will eventually regress, leading to the next phase.
4. Diestrus: This is the final stage of the estrous cycle and can last for several weeks or months. During this time, the female's reproductive tract returns to its resting state, and she is not sexually receptive. If pregnancy has occurred, the corpus luteum will continue to produce progesterone until the placenta takes over this function later in pregnancy.

It's important to note that the human menstrual cycle is different from the estrous cycle. While both cycles involve hormonal fluctuations and changes in the reproductive tract, the menstrual cycle includes a shedding of the uterine lining (menstruation) if fertilization does not occur, which is not a feature of the estrous cycle.

CDC25 phosphatases are a group of enzymes that play crucial roles in the regulation of the cell cycle, which is the series of events that cells undergo as they grow and divide. Specifically, CDC25 phosphatases function to remove inhibitory phosphates from certain cyclin-dependent kinases (CDKs), thereby activating them and allowing the cell cycle to progress.

There are three main types of CDC25 phosphatases in humans, known as CDC25A, CDC25B, and CDC25C. These enzymes are named after the original yeast homolog, called Cdc25, which was discovered to be essential for cell cycle progression.

CDC25 phosphatases are tightly regulated during the cell cycle, with their activity being controlled by various mechanisms such as phosphorylation, protein-protein interactions, and subcellular localization. Dysregulation of CDC25 phosphatases has been implicated in several human diseases, including cancer, where they can contribute to uncontrolled cell growth and division. Therefore, understanding the functions and regulation of CDC25 phosphatases is an important area of research in molecular biology and medicine.

The cell nucleus is a membrane-bound organelle found in the eukaryotic cells (cells with a true nucleus). It contains most of the cell's genetic material, organized as DNA molecules in complex with proteins, RNA molecules, and histones to form chromosomes.

The primary function of the cell nucleus is to regulate and control the activities of the cell, including growth, metabolism, protein synthesis, and reproduction. It also plays a crucial role in the process of mitosis (cell division) by separating and protecting the genetic material during this process. The nuclear membrane, or nuclear envelope, surrounding the nucleus is composed of two lipid bilayers with numerous pores that allow for the selective transport of molecules between the nucleoplasm (nucleus interior) and the cytoplasm (cell exterior).

The cell nucleus is a vital structure in eukaryotic cells, and its dysfunction can lead to various diseases, including cancer and genetic disorders.

Transcription factors are proteins that play a crucial role in regulating gene expression by controlling the transcription of DNA to messenger RNA (mRNA). They function by binding to specific DNA sequences, known as response elements, located in the promoter region or enhancer regions of target genes. This binding can either activate or repress the initiation of transcription, depending on the properties and interactions of the particular transcription factor. Transcription factors often act as part of a complex network of regulatory proteins that determine the precise spatiotemporal patterns of gene expression during development, differentiation, and homeostasis in an organism.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

'Tumor cells, cultured' refers to the process of removing cancerous cells from a tumor and growing them in controlled laboratory conditions. This is typically done by isolating the tumor cells from a patient's tissue sample, then placing them in a nutrient-rich environment that promotes their growth and multiplication.

The resulting cultured tumor cells can be used for various research purposes, including the study of cancer biology, drug development, and toxicity testing. They provide a valuable tool for researchers to better understand the behavior and characteristics of cancer cells outside of the human body, which can lead to the development of more effective cancer treatments.

It is important to note that cultured tumor cells may not always behave exactly the same way as they do in the human body, so findings from cell culture studies must be validated through further research, such as animal models or clinical trials.

E2F transcription factors are a family of proteins that play crucial roles in the regulation of the cell cycle, DNA repair, and apoptosis (programmed cell death). These factors bind to specific DNA sequences called E2F responsive elements, located in the promoter regions of target genes. They can act as either transcriptional activators or repressors, depending on which E2F family member is involved, the presence of co-factors, and the phase of the cell cycle.

The E2F family consists of eight members, divided into two groups based on their functions: activator E2Fs (E2F1, E2F2, and E2F3a) and repressor E2Fs (E2F3b, E2F4, E2F5, E2F6, and E2F7). Activator E2Fs promote the expression of genes required for cell cycle progression, DNA replication, and repair. Repressor E2Fs, on the other hand, inhibit the transcription of these same genes as well as genes involved in differentiation and apoptosis.

Dysregulation of E2F transcription factors has been implicated in various human diseases, including cancer. Overexpression or hyperactivation of activator E2Fs can lead to uncontrolled cell proliferation and tumorigenesis, while loss of function or inhibition of repressor E2Fs can result in impaired differentiation and increased susceptibility to malignancies. Therefore, understanding the roles and regulation of E2F transcription factors is essential for developing novel therapeutic strategies against cancer and other diseases associated with cell cycle dysregulation.

HeLa cells are a type of immortalized cell line used in scientific research. They are derived from a cancer that developed in the cervical tissue of Henrietta Lacks, an African-American woman, in 1951. After her death, cells taken from her tumor were found to be capable of continuous division and growth in a laboratory setting, making them an invaluable resource for medical research.

HeLa cells have been used in a wide range of scientific studies, including research on cancer, viruses, genetics, and drug development. They were the first human cell line to be successfully cloned and are able to grow rapidly in culture, doubling their population every 20-24 hours. This has made them an essential tool for many areas of biomedical research.

It is important to note that while HeLa cells have been instrumental in numerous scientific breakthroughs, the story of their origin raises ethical questions about informed consent and the use of human tissue in research.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Cyclin B1 is a type of cyclin protein that regulates the cell cycle, specifically the transition from G2 phase to mitosis (M phase) in eukaryotic cells. It forms a complex with and acts as a regulatory subunit of cyclin-dependent kinase 1 (CDK1), also known as CDC2. During the G2 phase, Cyclin B1 levels accumulate and upon reaching a certain threshold, it binds to CDK1 to form the maturation promoting factor (MPF). The activation of MPF triggers the onset of mitosis by promoting nuclear envelope breakdown, chromosome condensation, and other events required for cell division. After the completion of mitosis, Cyclin B1 is degraded by the ubiquitin-proteasome system, allowing the cell cycle to progress back into G1 phase.

"Saccharomyces cerevisiae" is not typically considered a medical term, but it is a scientific name used in the field of microbiology. It refers to a species of yeast that is commonly used in various industrial processes, such as baking and brewing. It's also widely used in scientific research due to its genetic tractability and eukaryotic cellular organization.

However, it does have some relevance to medical fields like medicine and nutrition. For example, certain strains of S. cerevisiae are used as probiotics, which can provide health benefits when consumed. They may help support gut health, enhance the immune system, and even assist in the digestion of certain nutrients.

In summary, "Saccharomyces cerevisiae" is a species of yeast with various industrial and potential medical applications.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

'Gene expression regulation' refers to the processes that control whether, when, and where a particular gene is expressed, meaning the production of a specific protein or functional RNA encoded by that gene. This complex mechanism can be influenced by various factors such as transcription factors, chromatin remodeling, DNA methylation, non-coding RNAs, and post-transcriptional modifications, among others. Proper regulation of gene expression is crucial for normal cellular function, development, and maintaining homeostasis in living organisms. Dysregulation of gene expression can lead to various diseases, including cancer and genetic disorders.

Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.

During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.

Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.

Cyclin D is a type of cyclin protein that plays a crucial role in the regulation of the cell cycle, which is the process by which cells grow and divide. Specifically, Cyclin D is involved in the G1 phase of the cell cycle and works in conjunction with its partner enzyme, cyclin-dependent kinase 4 (CDK4) or CDK6, to phosphorylate and regulate the activity of several key proteins that control the transition from G1 to S phase.

There are several different types of Cyclin D proteins, including Cyclin D1, Cyclin D2, and Cyclin D3, which are encoded by different genes but share similar structures and functions. Overexpression or dysregulation of Cyclin D has been implicated in the development of various human cancers, as it can lead to uncontrolled cell growth and division. Therefore, understanding the role of Cyclin D in the cell cycle and its regulation is important for developing potential cancer therapies.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

Cell differentiation is the process by which a less specialized cell, or stem cell, becomes a more specialized cell type with specific functions and structures. This process involves changes in gene expression, which are regulated by various intracellular signaling pathways and transcription factors. Differentiation results in the development of distinct cell types that make up tissues and organs in multicellular organisms. It is a crucial aspect of embryonic development, tissue repair, and maintenance of homeostasis in the body.

The Citric Acid Cycle, also known as the Krebs cycle or tricarboxylic acid (TCA) cycle, is a crucial metabolic pathway in the cell's powerhouse, the mitochondria. It plays a central role in the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins, into carbon dioxide and high-energy electrons. This process generates energy in the form of ATP (adenosine triphosphate), reducing equivalents (NADH and FADH2), and water.

The cycle begins with the condensation of acetyl-CoA with oxaloacetate, forming citrate. Through a series of enzyme-catalyzed reactions, citrate is converted back to oxaloacetate, releasing two molecules of carbon dioxide, one GTP (guanosine triphosphate), three NADH, one FADH2, and regenerating oxaloacetate to continue the cycle. The reduced coenzymes (NADH and FADH2) then donate their electrons to the electron transport chain, driving ATP synthesis through chemiosmosis. Overall, the Citric Acid Cycle is a vital part of cellular respiration, connecting various catabolic pathways and generating energy for the cell's metabolic needs.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Cell survival refers to the ability of a cell to continue living and functioning normally, despite being exposed to potentially harmful conditions or treatments. This can include exposure to toxins, radiation, chemotherapeutic drugs, or other stressors that can damage cells or interfere with their normal processes.

In scientific research, measures of cell survival are often used to evaluate the effectiveness of various therapies or treatments. For example, researchers may expose cells to a particular drug or treatment and then measure the percentage of cells that survive to assess its potential therapeutic value. Similarly, in toxicology studies, measures of cell survival can help to determine the safety of various chemicals or substances.

It's important to note that cell survival is not the same as cell proliferation, which refers to the ability of cells to divide and multiply. While some treatments may promote cell survival, they may also inhibit cell proliferation, making them useful for treating diseases such as cancer. Conversely, other treatments may be designed to specifically target and kill cancer cells, even if it means sacrificing some healthy cells in the process.

Bromodeoxyuridine (BrdU) is a synthetic thymidine analog that can be incorporated into DNA during cell replication. It is often used in research and medical settings as a marker for cell proliferation or as a tool to investigate DNA synthesis and repair. When cells are labeled with BrdU and then examined using immunofluorescence or other detection techniques, the presence of BrdU can indicate which cells have recently divided or are actively synthesizing DNA.

In medical contexts, BrdU has been used in cancer research to study tumor growth and response to treatment. It has also been explored as a potential therapeutic agent for certain conditions, such as neurodegenerative diseases, where promoting cell proliferation and replacement of damaged cells may be beneficial. However, its use as a therapeutic agent is still experimental and requires further investigation.

E2F1 is a member of the E2F family of transcription factors, which are involved in the regulation of cell cycle progression and apoptosis (programmed cell death). Specifically, E2F1 plays a role as a transcriptional activator, binding to specific DNA sequences and promoting the expression of genes required for the G1/S transition of the cell cycle.

In more detail, E2F1 forms a complex with a retinoblastoma protein (pRb) in the G0 and early G1 phases of the cell cycle. When pRb is phosphorylated by cyclin-dependent kinases during the late G1 phase, E2F1 is released and can then bind to its target DNA sequences and activate transcription of genes involved in DNA replication and cell cycle progression.

However, if E2F1 is overexpressed or activated inappropriately, it can also promote apoptosis, making it a key player in both cell proliferation and cell death pathways. Dysregulation of E2F1 has been implicated in the development of various human cancers, including breast, lung, and prostate cancer.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Saccharomyces cerevisiae proteins are the proteins that are produced by the budding yeast, Saccharomyces cerevisiae. This organism is a single-celled eukaryote that has been widely used as a model organism in scientific research for many years due to its relatively simple genetic makeup and its similarity to higher eukaryotic cells.

The genome of Saccharomyces cerevisiae has been fully sequenced, and it is estimated to contain approximately 6,000 genes that encode proteins. These proteins play a wide variety of roles in the cell, including catalyzing metabolic reactions, regulating gene expression, maintaining the structure of the cell, and responding to environmental stimuli.

Many Saccharomyces cerevisiae proteins have human homologs and are involved in similar biological processes, making this organism a valuable tool for studying human disease. For example, many of the proteins involved in DNA replication, repair, and recombination in yeast have human counterparts that are associated with cancer and other diseases. By studying these proteins in yeast, researchers can gain insights into their function and regulation in humans, which may lead to new treatments for disease.

Western blotting is a laboratory technique used in molecular biology to detect and quantify specific proteins in a mixture of many different proteins. This technique is commonly used to confirm the expression of a protein of interest, determine its size, and investigate its post-translational modifications. The name "Western" blotting distinguishes this technique from Southern blotting (for DNA) and Northern blotting (for RNA).

The Western blotting procedure involves several steps:

1. Protein extraction: The sample containing the proteins of interest is first extracted, often by breaking open cells or tissues and using a buffer to extract the proteins.
2. Separation of proteins by electrophoresis: The extracted proteins are then separated based on their size by loading them onto a polyacrylamide gel and running an electric current through the gel (a process called sodium dodecyl sulfate-polyacrylamide gel electrophoresis or SDS-PAGE). This separates the proteins according to their molecular weight, with smaller proteins migrating faster than larger ones.
3. Transfer of proteins to a membrane: After separation, the proteins are transferred from the gel onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric current in a process called blotting. This creates a replica of the protein pattern on the gel but now immobilized on the membrane for further analysis.
4. Blocking: The membrane is then blocked with a blocking agent, such as non-fat dry milk or bovine serum albumin (BSA), to prevent non-specific binding of antibodies in subsequent steps.
5. Primary antibody incubation: A primary antibody that specifically recognizes the protein of interest is added and allowed to bind to its target protein on the membrane. This step may be performed at room temperature or 4°C overnight, depending on the antibody's properties.
6. Washing: The membrane is washed with a buffer to remove unbound primary antibodies.
7. Secondary antibody incubation: A secondary antibody that recognizes the primary antibody (often coupled to an enzyme or fluorophore) is added and allowed to bind to the primary antibody. This step may involve using a horseradish peroxidase (HRP)-conjugated or alkaline phosphatase (AP)-conjugated secondary antibody, depending on the detection method used later.
8. Washing: The membrane is washed again to remove unbound secondary antibodies.
9. Detection: A detection reagent is added to visualize the protein of interest by detecting the signal generated from the enzyme-conjugated or fluorophore-conjugated secondary antibody. This can be done using chemiluminescent, colorimetric, or fluorescent methods.
10. Analysis: The resulting image is analyzed to determine the presence and quantity of the protein of interest in the sample.

Western blotting is a powerful technique for identifying and quantifying specific proteins within complex mixtures. It can be used to study protein expression, post-translational modifications, protein-protein interactions, and more. However, it requires careful optimization and validation to ensure accurate and reproducible results.

The S phase cell cycle checkpoints are mechanisms that ensure the accurate and timely progression through the DNA synthesis (S) phase of the eukaryotic cell cycle. These checkpoints monitor the completion of DNA replication and the proper repair of any DNA damage before the cell moves on to the next phase, namely the mitosis (M) phase.

The S phase checkpoint is primarily focused on detecting and responding to DNA damage that may occur during the replication process. When DNA damage is detected, the checkpoint machinery triggers a series of events that lead to the activation of cell cycle arrest, DNA repair pathways, and/or apoptosis (programmed cell death) if the damage is too severe or cannot be repaired.

The primary components of the S phase checkpoint include sensors, transducers, and effectors. The sensors detect DNA damage or stalled replication forks, while the transducers transmit and amplify the signal to activate the effectors. The effectors then bring about cell cycle arrest, allowing time for repair or initiating apoptosis if necessary.

Overall, the S phase cell cycle checkpoints play a crucial role in maintaining genomic stability and preventing the propagation of cells with damaged DNA, which can lead to tumorigenesis and other diseases.

Protein kinases are a group of enzymes that play a crucial role in many cellular processes by adding phosphate groups to other proteins, a process known as phosphorylation. This modification can activate or deactivate the target protein's function, thereby regulating various signaling pathways within the cell. Protein kinases are essential for numerous biological functions, including metabolism, signal transduction, cell cycle progression, and apoptosis (programmed cell death). Abnormal regulation of protein kinases has been implicated in several diseases, such as cancer, diabetes, and neurological disorders.

Down-regulation is a process that occurs in response to various stimuli, where the number or sensitivity of cell surface receptors or the expression of specific genes is decreased. This process helps maintain homeostasis within cells and tissues by reducing the ability of cells to respond to certain signals or molecules.

In the context of cell surface receptors, down-regulation can occur through several mechanisms:

1. Receptor internalization: After binding to their ligands, receptors can be internalized into the cell through endocytosis. Once inside the cell, these receptors may be degraded or recycled back to the cell surface in smaller numbers.
2. Reduced receptor synthesis: Down-regulation can also occur at the transcriptional level, where the expression of genes encoding for specific receptors is decreased, leading to fewer receptors being produced.
3. Receptor desensitization: Prolonged exposure to a ligand can lead to a decrease in receptor sensitivity or affinity, making it more difficult for the cell to respond to the signal.

In the context of gene expression, down-regulation refers to the decreased transcription and/or stability of specific mRNAs, leading to reduced protein levels. This process can be induced by various factors, including microRNA (miRNA)-mediated regulation, histone modification, or DNA methylation.

Down-regulation is an essential mechanism in many physiological processes and can also contribute to the development of several diseases, such as cancer and neurodegenerative disorders.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Cyclin D3 is a type of cyclin protein that regulates the cell cycle, particularly during the G1 phase. It forms a complex with and acts as a regulatory subunit of CDK4 or CDK6, which are cyclin-dependent kinases. This complex plays a crucial role in phosphorylating and inactivating the retinoblastoma protein (pRb), leading to the release of E2F transcription factors that promote the expression of genes required for DNA replication and cell cycle progression into the S phase.

Cyclin D3 is primarily expressed in activated lymphocytes and is essential for normal immune function, as well as in certain tissues during development. Alterations in CYCLIN D3 gene expression or function have been implicated in several types of cancer, such as leukemias and lymphomas, due to their role in uncontrolled cell proliferation.

Cyclin-dependent kinase inhibitor proteins (CDKIs) are a family of regulatory proteins that play a crucial role in the control of the cell cycle. They function by binding to and inhibiting the activity of cyclin-dependent kinases (CDKs), which are serine/threonine protein kinases that help drive the progression of the cell cycle.

There are two main families of CDKIs: the Ink4 family and the Cip/Kip family. The Ink4 family members, including p16INK4a, p15INK4b, p18INK4c, and p19INK4d, specifically inhibit CDK4 and CDK6, preventing their association with cyclin D and thus blocking the transition from G1 to S phase of the cell cycle. The Cip/Kip family members, including p21CIP1, p27KIP1, and p57KIP2, inhibit a broader range of CDKs, including CDK1, CDK2, CDK4, and CDK6, and can regulate multiple stages of the cell cycle.

CDKIs play important roles in various biological processes, such as cell growth, differentiation, and apoptosis. Dysregulation of CDKI function has been implicated in several human diseases, including cancer, where loss or mutation of CDKIs can lead to uncontrolled cell proliferation and tumorigenesis. Therefore, CDKIs are attractive targets for the development of anti-cancer therapies.

Fibroblasts are specialized cells that play a critical role in the body's immune response and wound healing process. They are responsible for producing and maintaining the extracellular matrix (ECM), which is the non-cellular component present within all tissues and organs, providing structural support and biochemical signals for surrounding cells.

Fibroblasts produce various ECM proteins such as collagens, elastin, fibronectin, and laminins, forming a complex network of fibers that give tissues their strength and flexibility. They also help in the regulation of tissue homeostasis by controlling the turnover of ECM components through the process of remodeling.

In response to injury or infection, fibroblasts become activated and start to proliferate rapidly, migrating towards the site of damage. Here, they participate in the inflammatory response, releasing cytokines and chemokines that attract immune cells to the area. Additionally, they deposit new ECM components to help repair the damaged tissue and restore its functionality.

Dysregulation of fibroblast activity has been implicated in several pathological conditions, including fibrosis (excessive scarring), cancer (where they can contribute to tumor growth and progression), and autoimmune diseases (such as rheumatoid arthritis).

Antineoplastic agents are a class of drugs used to treat malignant neoplasms or cancer. These agents work by inhibiting the growth and proliferation of cancer cells, either by killing them or preventing their division and replication. Antineoplastic agents can be classified based on their mechanism of action, such as alkylating agents, antimetabolites, topoisomerase inhibitors, mitotic inhibitors, and targeted therapy agents.

Alkylating agents work by adding alkyl groups to DNA, which can cause cross-linking of DNA strands and ultimately lead to cell death. Antimetabolites interfere with the metabolic processes necessary for DNA synthesis and replication, while topoisomerase inhibitors prevent the relaxation of supercoiled DNA during replication. Mitotic inhibitors disrupt the normal functioning of the mitotic spindle, which is essential for cell division. Targeted therapy agents are designed to target specific molecular abnormalities in cancer cells, such as mutated oncogenes or dysregulated signaling pathways.

It's important to note that antineoplastic agents can also affect normal cells and tissues, leading to various side effects such as nausea, vomiting, hair loss, and myelosuppression (suppression of bone marrow function). Therefore, the use of these drugs requires careful monitoring and management of their potential adverse effects.

Fungal proteins are a type of protein that is specifically produced and present in fungi, which are a group of eukaryotic organisms that include microorganisms such as yeasts and molds. These proteins play various roles in the growth, development, and survival of fungi. They can be involved in the structure and function of fungal cells, metabolism, pathogenesis, and other cellular processes. Some fungal proteins can also have important implications for human health, both in terms of their potential use as therapeutic targets and as allergens or toxins that can cause disease.

Fungal proteins can be classified into different categories based on their functions, such as enzymes, structural proteins, signaling proteins, and toxins. Enzymes are proteins that catalyze chemical reactions in fungal cells, while structural proteins provide support and protection for the cell. Signaling proteins are involved in communication between cells and regulation of various cellular processes, and toxins are proteins that can cause harm to other organisms, including humans.

Understanding the structure and function of fungal proteins is important for developing new treatments for fungal infections, as well as for understanding the basic biology of fungi. Research on fungal proteins has led to the development of several antifungal drugs that target specific fungal enzymes or other proteins, providing effective treatment options for a range of fungal diseases. Additionally, further study of fungal proteins may reveal new targets for drug development and help improve our ability to diagnose and treat fungal infections.

Transfection is a term used in molecular biology that refers to the process of deliberately introducing foreign genetic material (DNA, RNA or artificial gene constructs) into cells. This is typically done using chemical or physical methods, such as lipofection or electroporation. Transfection is widely used in research and medical settings for various purposes, including studying gene function, producing proteins, developing gene therapies, and creating genetically modified organisms. It's important to note that transfection is different from transduction, which is the process of introducing genetic material into cells using viruses as vectors.

I apologize for any confusion, but "Schizosaccharomyces" is not a medical term. It is a genus name in the field of microbiology and genetics, referring to a group of budding, tear-shaped yeasts that are widely used as model organisms in scientific research. The most well-known species within this genus is Schizosaccharomyces pombe, which has been extensively studied for its cell cycle regulation, DNA repair mechanisms, and other fundamental biological processes.

If you have any questions related to medical terminology or health-related topics, I would be happy to help.

Histones are highly alkaline proteins found in the chromatin of eukaryotic cells. They are rich in basic amino acid residues, such as arginine and lysine, which give them their positive charge. Histones play a crucial role in packaging DNA into a more compact structure within the nucleus by forming a complex with it called a nucleosome. Each nucleosome contains about 146 base pairs of DNA wrapped around an octamer of eight histone proteins (two each of H2A, H2B, H3, and H4). The N-terminal tails of these histones are subject to various post-translational modifications, such as methylation, acetylation, and phosphorylation, which can influence chromatin structure and gene expression. Histone variants also exist, which can contribute to the regulation of specific genes and other nuclear processes.

M Phase cell cycle checkpoints are control mechanisms that ensure the proper completion of the M phase (mitosis or meiosis) of the cell cycle. These checkpoints verify that certain conditions are met before the cell proceeds to the next phase of the cell cycle, thus helping to maintain genomic stability and prevent errors such as chromosomal mutations or aneuploidy.

There are two main M Phase cell cycle checkpoints:

1. The G2/M Checkpoint: This checkpoint is activated at the end of the G2 phase and verifies that all DNA has been replicated accurately, and that there are no DNA damages or other issues that could interfere with mitosis. If any problems are detected, the cell cycle is halted until they can be resolved.
2. The Mitotic Spindle Checkpoint: This checkpoint ensures that all chromosomes have attached properly to the spindle apparatus and that they will be equally distributed to the two resulting daughter cells during mitosis. If any chromosomes are not properly attached or if there is an issue with the spindle apparatus, the cell cycle is paused until these problems are corrected.

These checkpoints play a crucial role in maintaining genomic stability and preventing the development of cancer and other diseases.

Proliferating Cell Nuclear Antigen (PCNA) is a protein that plays an essential role in the process of DNA replication and repair in eukaryotic cells. It functions as a cofactor for DNA polymerase delta, enhancing its activity during DNA synthesis. PCNA forms a sliding clamp around DNA, allowing it to move along the template and coordinate the actions of various enzymes involved in DNA metabolism.

PCNA is often used as a marker for cell proliferation because its levels increase in cells that are actively dividing or have been stimulated to enter the cell cycle. Immunostaining techniques can be used to detect PCNA and determine the proliferative status of tissues or cultures. In this context, 'proliferating' refers to the rapid multiplication of cells through cell division.

Neoplastic gene expression regulation refers to the processes that control the production of proteins and other molecules from genes in neoplastic cells, or cells that are part of a tumor or cancer. In a normal cell, gene expression is tightly regulated to ensure that the right genes are turned on or off at the right time. However, in cancer cells, this regulation can be disrupted, leading to the overexpression or underexpression of certain genes.

Neoplastic gene expression regulation can be affected by a variety of factors, including genetic mutations, epigenetic changes, and signals from the tumor microenvironment. These changes can lead to the activation of oncogenes (genes that promote cancer growth and development) or the inactivation of tumor suppressor genes (genes that prevent cancer).

Understanding neoplastic gene expression regulation is important for developing new therapies for cancer, as targeting specific genes or pathways involved in this process can help to inhibit cancer growth and progression.

Medical Definition:
Microtubule-associated proteins (MAPs) are a diverse group of proteins that bind to microtubules, which are key components of the cytoskeleton in eukaryotic cells. MAPs play crucial roles in regulating microtubule dynamics and stability, as well as in mediating interactions between microtubules and other cellular structures. They can be classified into several categories based on their functions, including:

1. Microtubule stabilizers: These MAPs promote the assembly of microtubules and protect them from disassembly by enhancing their stability. Examples include tau proteins and MAP2.
2. Microtubule dynamics regulators: These MAPs modulate the rate of microtubule polymerization and depolymerization, allowing for dynamic reorganization of the cytoskeleton during cell division and other processes. Examples include stathmin and XMAP215.
3. Microtubule motor proteins: These MAPs use energy from ATP hydrolysis to move along microtubules, transporting various cargoes within the cell. Examples include kinesin and dynein.
4. Adapter proteins: These MAPs facilitate interactions between microtubules and other cellular structures, such as membranes, organelles, or signaling molecules. Examples include MAP4 and CLASPs.

Dysregulation of MAPs has been implicated in several diseases, including neurodegenerative disorders like Alzheimer's disease (where tau proteins form abnormal aggregates called neurofibrillary tangles) and cancer (where altered microtubule dynamics can contribute to uncontrolled cell division).

Proto-oncogene proteins are normal cellular proteins that play crucial roles in various cellular processes, such as signal transduction, cell cycle regulation, and apoptosis (programmed cell death). They are involved in the regulation of cell growth, differentiation, and survival under physiological conditions.

When proto-oncogene proteins undergo mutations or aberrations in their expression levels, they can transform into oncogenic forms, leading to uncontrolled cell growth and division. These altered proteins are then referred to as oncogene products or oncoproteins. Oncogenic mutations can occur due to various factors, including genetic predisposition, environmental exposures, and aging.

Examples of proto-oncogene proteins include:

1. Ras proteins: Involved in signal transduction pathways that regulate cell growth and differentiation. Activating mutations in Ras genes are found in various human cancers.
2. Myc proteins: Regulate gene expression related to cell cycle progression, apoptosis, and metabolism. Overexpression of Myc proteins is associated with several types of cancer.
3. EGFR (Epidermal Growth Factor Receptor): A transmembrane receptor tyrosine kinase that regulates cell proliferation, survival, and differentiation. Mutations or overexpression of EGFR are linked to various malignancies, such as lung cancer and glioblastoma.
4. Src family kinases: Intracellular tyrosine kinases that regulate signal transduction pathways involved in cell proliferation, survival, and migration. Dysregulation of Src family kinases is implicated in several types of cancer.
5. Abl kinases: Cytoplasmic tyrosine kinases that regulate various cellular processes, including cell growth, differentiation, and stress responses. Aberrant activation of Abl kinases, as seen in chronic myelogenous leukemia (CML), leads to uncontrolled cell proliferation.

Understanding the roles of proto-oncogene proteins and their dysregulation in cancer development is essential for developing targeted cancer therapies that aim to inhibit or modulate these aberrant signaling pathways.

Gene expression profiling is a laboratory technique used to measure the activity (expression) of thousands of genes at once. This technique allows researchers and clinicians to identify which genes are turned on or off in a particular cell, tissue, or organism under specific conditions, such as during health, disease, development, or in response to various treatments.

The process typically involves isolating RNA from the cells or tissues of interest, converting it into complementary DNA (cDNA), and then using microarray or high-throughput sequencing technologies to determine which genes are expressed and at what levels. The resulting data can be used to identify patterns of gene expression that are associated with specific biological states or processes, providing valuable insights into the underlying molecular mechanisms of diseases and potential targets for therapeutic intervention.

In recent years, gene expression profiling has become an essential tool in various fields, including cancer research, drug discovery, and personalized medicine, where it is used to identify biomarkers of disease, predict patient outcomes, and guide treatment decisions.

Hydroxyurea is an antimetabolite drug that is primarily used in the treatment of myeloproliferative disorders such as chronic myelogenous leukemia (CML), essential thrombocythemia, and polycythemia vera. It works by interfering with the synthesis of DNA, which inhibits the growth of cancer cells.

In addition to its use in cancer therapy, hydroxyurea is also used off-label for the management of sickle cell disease. In this context, it helps to reduce the frequency and severity of painful vaso-occlusive crises by increasing the production of fetal hemoglobin (HbF), which decreases the formation of sickled red blood cells.

The medical definition of hydroxyurea is:

A hydantoin derivative and antimetabolite that inhibits ribonucleoside diphosphate reductase, thereby interfering with DNA synthesis. It has been used as an antineoplastic agent, particularly in the treatment of myeloproliferative disorders, and more recently for the management of sickle cell disease to reduce the frequency and severity of painful vaso-occlusive crises by increasing fetal hemoglobin production.

Small interfering RNA (siRNA) is a type of short, double-stranded RNA molecule that plays a role in the RNA interference (RNAi) pathway. The RNAi pathway is a natural cellular process that regulates gene expression by targeting and destroying specific messenger RNA (mRNA) molecules, thereby preventing the translation of those mRNAs into proteins.

SiRNAs are typically 20-25 base pairs in length and are generated from longer double-stranded RNA precursors called hairpin RNAs or dsRNAs by an enzyme called Dicer. Once generated, siRNAs associate with a protein complex called the RNA-induced silencing complex (RISC), which uses one strand of the siRNA (the guide strand) to recognize and bind to complementary sequences in the target mRNA. The RISC then cleaves the target mRNA, leading to its degradation and the inhibition of protein synthesis.

SiRNAs have emerged as a powerful tool for studying gene function and have shown promise as therapeutic agents for a variety of diseases, including viral infections, cancer, and genetic disorders. However, their use as therapeutics is still in the early stages of development, and there are challenges associated with delivering siRNAs to specific cells and tissues in the body.

Cyclin-Dependent Kinase Inhibitor p16, also known as CDKN2A or INK4a, is a protein that regulates the cell cycle. It functions as an inhibitor of cyclin-dependent kinases (CDKs) 4 and 6, which are enzymes that play a crucial role in regulating the progression of the cell cycle.

The p16 protein is produced in response to various signals, including DNA damage and oncogene activation, and its main function is to prevent the phosphorylation and activation of the retinoblastoma protein (pRb) by CDK4/6. When pRb is not phosphorylated, it binds to and inhibits the E2F transcription factor, which results in the suppression of genes required for cell cycle progression.

Therefore, p16 acts as a tumor suppressor protein by preventing the uncontrolled proliferation of cells that can lead to cancer. Mutations or deletions in the CDKN2A gene, which encodes the p16 protein, have been found in many types of human cancers, including lung, breast, and head and neck cancers.

'Caulobacter crescentus' is a gram-negative, oligotrophic aquatic bacterium that is commonly found in freshwater environments. It is known for its distinctive curved or "crescent" shape and the presence of a holdfast structure at one end, which allows it to attach to surfaces. 'Caulobacter crescentus' has a complex life cycle involving two distinct cell types: swarmer cells, which are motile and can swim in search of new surfaces to colonize, and stalked cells, which are non-motile and have a long, thin stalk that extends from the holdfast end. This bacterium is often used as a model organism for studying cell differentiation, asymmetric cell division, and the regulation of gene expression in response to environmental signals.

Cyclin-Dependent Kinase 6 (CDK6) is a type of enzyme known as a protein kinase, which adds phosphate groups to other proteins in the cell. CDK6 is primarily involved in regulating the cell cycle, the process by which cells divide and grow.

CDK6 functions by binding to cyclin proteins, forming active complexes that help drive the progression of the cell cycle from one phase to the next. Specifically, CDK6 plays a crucial role in the transition from the G1 phase to the S phase of the cell cycle, where DNA replication occurs.

CDK6 activity is tightly regulated by various mechanisms, including phosphorylation and dephosphorylation, as well as by binding to inhibitory proteins such as p16INK4a and p21CIP1. Dysregulation of CDK6 has been implicated in the development of several types of cancer, making it a potential target for cancer therapy.

Promoter regions in genetics refer to specific DNA sequences located near the transcription start site of a gene. They serve as binding sites for RNA polymerase and various transcription factors that regulate the initiation of gene transcription. These regulatory elements help control the rate of transcription and, therefore, the level of gene expression. Promoter regions can be composed of different types of sequences, such as the TATA box and CAAT box, and their organization and composition can vary between different genes and species.

Cyclin D2 is a type of cyclin protein that regulates the cell cycle, particularly in the G1 phase. It forms a complex with and acts as a regulatory subunit of cyclin-dependent kinase 4 (CDK4) or CDK6, promoting the transition from G1 to S phase of the cell cycle. The expression of cyclin D2 is regulated by various growth factors, hormones, and oncogenes, and its dysregulation has been implicated in the development of several types of cancer.

Transcription factor DP1 (TFDP1) is not a specific medical term, but it is a term used in molecular biology and genetics. TFDP1 is a protein that functions as a transcription factor, which means it helps regulate the expression of genes by binding to specific DNA sequences and controlling the rate of transcription of those genes into messenger RNA (mRNA).

TFDP1 typically forms a complex with another transcription factor called E2F, and this complex plays a critical role in regulating the cell cycle and promoting cell division. TFDP1 can act as both a transcriptional activator and repressor, depending on which E2F family member it binds to and the specific context of the cell.

Mutations or dysregulation of TFDP1 have been implicated in various human diseases, including cancer. For example, overexpression of TFDP1 has been observed in several types of cancer, such as breast, lung, and prostate cancer, and is often associated with poor clinical outcomes. Therefore, understanding the role of TFDP1 in gene regulation and cellular processes may provide insights into the development of new therapeutic strategies for treating human diseases.

Mimosine is not a medical term per se, but it is a chemical compound that has been studied in the context of biomedical research. Mimosine is an alkaloid found in certain plants, including the mimosa tree (Leucaena leucocephala). It has been shown to have various biological activities, such as anti-proliferative and cytotoxic effects on certain types of cells. However, it is not a term that is commonly used in medical diagnoses or treatments.

In terms of its chemical structure, mimosine is an amino acid that contains a pyrrolidone ring with a hydroxyl group at the 3-position and a carboxylic acid group at the 2-position. It can inhibit certain enzymes involved in DNA replication and repair, which may contribute to its anti-proliferative effects.

It's worth noting that mimosine has been studied for its potential therapeutic benefits, such as its ability to inhibit the growth of cancer cells. However, more research is needed to determine its safety and efficacy in humans before it can be considered a viable treatment option.

Enzyme inhibitors are substances that bind to an enzyme and decrease its activity, preventing it from catalyzing a chemical reaction in the body. They can work by several mechanisms, including blocking the active site where the substrate binds, or binding to another site on the enzyme to change its shape and prevent substrate binding. Enzyme inhibitors are often used as drugs to treat various medical conditions, such as high blood pressure, abnormal heart rhythms, and bacterial infections. They can also be found naturally in some foods and plants, and can be used in research to understand enzyme function and regulation.

Ubiquitin-Protein Ligase Complexes, also known as E3 ubiquitin ligases, are a group of enzymes that play a crucial role in the ubiquitination process. Ubiquitination is a post-translational modification where ubiquitin molecules are attached to specific target proteins, marking them for degradation by the proteasome or altering their function, localization, or interaction with other proteins.

The ubiquitination process involves three main steps:

1. Ubiquitin activation: Ubiquitin is activated by an E1 ubiquitin-activating enzyme in an ATP-dependent reaction.
2. Ubiquitin conjugation: The activated ubiquitin is then transferred to an E2 ubiquitin-conjugating enzyme.
3. Ubiquitin ligation: Finally, the E2 ubiquitin-conjugating enzyme interacts with a specific E3 ubiquitin ligase complex, which facilitates the transfer and ligation of ubiquitin to the target protein.

Ubiquitin-Protein Ligase Complexes are responsible for recognizing and binding to specific substrate proteins, ensuring that ubiquitination occurs on the correct targets. They can be divided into three main categories based on their structural features and mechanisms of action:

1. Really Interesting New Gene (RING) finger E3 ligases: These E3 ligases contain a RING finger domain, which directly interacts with both the E2 ubiquitin-conjugating enzyme and the substrate protein. They facilitate the transfer of ubiquitin from the E2 to the target protein by bringing them into close proximity.
2. Homologous to E6-AP C terminus (HECT) E3 ligases: These E3 ligases contain a HECT domain, which interacts with the E2 ubiquitin-conjugating enzyme and forms a thioester bond with ubiquitin before transferring it to the substrate protein.
3. RING-between-RING (RBR) E3 ligases: These E3 ligases contain both RING finger and HECT-like domains, which allow them to function similarly to both RING finger and HECT E3 ligases. They first form a thioester bond with ubiquitin using their RING1 domain before transferring it to the substrate protein via their RING2 domain.

Dysregulation of Ubiquitin-Protein Ligase Complexes has been implicated in various diseases, including cancer and neurodegenerative disorders. Understanding their mechanisms and functions can provide valuable insights into disease pathogenesis and potential therapeutic strategies.

Carrier proteins, also known as transport proteins, are a type of protein that facilitates the movement of molecules across cell membranes. They are responsible for the selective and active transport of ions, sugars, amino acids, and other molecules from one side of the membrane to the other, against their concentration gradient. This process requires energy, usually in the form of ATP (adenosine triphosphate).

Carrier proteins have a specific binding site for the molecule they transport, and undergo conformational changes upon binding, which allows them to move the molecule across the membrane. Once the molecule has been transported, the carrier protein returns to its original conformation, ready to bind and transport another molecule.

Carrier proteins play a crucial role in maintaining the balance of ions and other molecules inside and outside of cells, and are essential for many physiological processes, including nerve impulse transmission, muscle contraction, and nutrient uptake.

RNA interference (RNAi) is a biological process in which RNA molecules inhibit the expression of specific genes. This process is mediated by small RNA molecules, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), that bind to complementary sequences on messenger RNA (mRNA) molecules, leading to their degradation or translation inhibition.

RNAi plays a crucial role in regulating gene expression and defending against foreign genetic elements, such as viruses and transposons. It has also emerged as an important tool for studying gene function and developing therapeutic strategies for various diseases, including cancer and viral infections.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Retinoblastoma-Binding Protein 1 (RBP1) is not a medical term itself, but it is a protein that has been studied in the context of cancer research, including retinoblastoma. According to scientific and medical literature, RBP1 is a protein that binds to the retinoblastoma protein (pRb), which is a tumor suppressor protein. The binding of RBP1 to pRb can influence the activity of this tumor suppressor and contribute to the regulation of the cell cycle and cell growth.

In the case of retinoblastoma, mutations in the RB1 gene, which encodes for the pRb protein, have been identified as a cause of this rare eye cancer in children. However, the role of RBP1 in retinoblastoma or other cancers is not well-defined and requires further research to fully understand its implications in disease development and potential therapeutic targets.

Gene expression is the process by which the information encoded in a gene is used to synthesize a functional gene product, such as a protein or RNA molecule. This process involves several steps: transcription, RNA processing, and translation. During transcription, the genetic information in DNA is copied into a complementary RNA molecule, known as messenger RNA (mRNA). The mRNA then undergoes RNA processing, which includes adding a cap and tail to the mRNA and splicing out non-coding regions called introns. The resulting mature mRNA is then translated into a protein on ribosomes in the cytoplasm through the process of translation.

The regulation of gene expression is a complex and highly controlled process that allows cells to respond to changes in their environment, such as growth factors, hormones, and stress signals. This regulation can occur at various stages of gene expression, including transcriptional activation or repression, RNA processing, mRNA stability, and translation. Dysregulation of gene expression has been implicated in many diseases, including cancer, genetic disorders, and neurological conditions.

The spindle apparatus is a microtubule-based structure that plays a crucial role in the process of cell division, specifically during mitosis and meiosis. It consists of three main components:

1. The spindle poles: These are organized structures composed of microtubules and associated proteins that serve as the anchoring points for the spindle fibers. In animal cells, these poles are typically formed by centrosomes, while in plant cells, they form around nucleation sites called microtubule-organizing centers (MTOCs).
2. The spindle fibers: These are dynamic arrays of microtubules that extend between the two spindle poles. They can be categorized into three types: kinetochore fibers, which connect to the kinetochores on chromosomes; astral fibers, which radiate from the spindle poles and help position the spindle within the cell; and interpolar fibers, which lie between the two spindle poles and contribute to their separation during anaphase.
3. Regulatory proteins: Various motor proteins, such as dynein and kinesin, as well as non-motor proteins like tubulin and septins, are involved in the assembly, maintenance, and dynamics of the spindle apparatus. These proteins help to generate forces that move chromosomes, position the spindle, and ultimately segregate genetic material between two daughter cells during cell division.

The spindle apparatus is essential for ensuring accurate chromosome separation and maintaining genomic stability during cell division. Dysfunction of the spindle apparatus can lead to various abnormalities, including aneuploidy (abnormal number of chromosomes) and chromosomal instability, which have been implicated in several diseases, such as cancer and developmental disorders.

DNA repair is the process by which cells identify and correct damage to the DNA molecules that encode their genome. DNA can be damaged by a variety of internal and external factors, such as radiation, chemicals, and metabolic byproducts. If left unrepaired, this damage can lead to mutations, which may in turn lead to cancer and other diseases.

There are several different mechanisms for repairing DNA damage, including:

1. Base excision repair (BER): This process repairs damage to a single base in the DNA molecule. An enzyme called a glycosylase removes the damaged base, leaving a gap that is then filled in by other enzymes.
2. Nucleotide excision repair (NER): This process repairs more severe damage, such as bulky adducts or crosslinks between the two strands of the DNA molecule. An enzyme cuts out a section of the damaged DNA, and the gap is then filled in by other enzymes.
3. Mismatch repair (MMR): This process repairs errors that occur during DNA replication, such as mismatched bases or small insertions or deletions. Specialized enzymes recognize the error and remove a section of the newly synthesized strand, which is then replaced by new nucleotides.
4. Double-strand break repair (DSBR): This process repairs breaks in both strands of the DNA molecule. There are two main pathways for DSBR: non-homologous end joining (NHEJ) and homologous recombination (HR). NHEJ directly rejoins the broken ends, while HR uses a template from a sister chromatid to repair the break.

Overall, DNA repair is a crucial process that helps maintain genome stability and prevent the development of diseases caused by genetic mutations.

'Life cycle stages' is a term used in the context of public health and medicine to describe the different stages that an organism goes through during its lifetime. This concept is particularly important in the field of epidemiology, where understanding the life cycle stages of infectious agents (such as bacteria, viruses, parasites) can help inform strategies for disease prevention and control.

The life cycle stages of an infectious agent may include various forms such as spores, cysts, trophozoites, schizonts, or vectors, among others, depending on the specific organism. Each stage may have different characteristics, such as resistance to environmental factors, susceptibility to drugs, and ability to transmit infection.

For example, the life cycle stages of the malaria parasite include sporozoites (the infective form transmitted by mosquitoes), merozoites (the form that infects red blood cells), trophozoites (the feeding stage inside red blood cells), schizonts (the replicating stage inside red blood cells), and gametocytes (the sexual stage that can be taken up by mosquitoes to continue the life cycle).

Understanding the life cycle stages of an infectious agent is critical for developing effective interventions, such as vaccines, drugs, or other control measures. For example, targeting a specific life cycle stage with a drug may prevent transmission or reduce the severity of disease. Similarly, designing a vaccine to elicit immunity against a particular life cycle stage may provide protection against infection or disease.

The Anaphase-Promoting Complex/Cyclosome (APC/C) is a large E3 ubiquitin ligase complex that plays a crucial role in the regulation of the cell cycle. It is responsible for targeting specific proteins for degradation by the proteasome, which is a multi-subunit protein complex that mediates the controlled breakdown of ubiquitinated proteins.

During anaphase, the final stage of mitosis, the APC/C becomes active and triggers the degradation of several key regulatory proteins, including securin and cyclin B. The destruction of these proteins allows for the separation of chromosomes and the completion of cell division.

The APC/C is composed of multiple subunits, including a catalytic core that binds to ubiquitin-conjugating enzymes (E2s) and several coactivators that regulate its activity. The activation of the APC/C requires the binding of one of two coactivators, Cdc20 or CDH1, which recognize specific substrates for degradation.

Dysregulation of the APC/C has been implicated in various human diseases, including cancer and neurodegenerative disorders. Therefore, understanding the mechanisms that regulate its activity is an important area of research with potential therapeutic implications.

Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) is a laboratory technique used in molecular biology to amplify and detect specific DNA sequences. This technique is particularly useful for the detection and quantification of RNA viruses, as well as for the analysis of gene expression.

The process involves two main steps: reverse transcription and polymerase chain reaction (PCR). In the first step, reverse transcriptase enzyme is used to convert RNA into complementary DNA (cDNA) by reading the template provided by the RNA molecule. This cDNA then serves as a template for the PCR amplification step.

In the second step, the PCR reaction uses two primers that flank the target DNA sequence and a thermostable polymerase enzyme to repeatedly copy the targeted cDNA sequence. The reaction mixture is heated and cooled in cycles, allowing the primers to anneal to the template, and the polymerase to extend the new strand. This results in exponential amplification of the target DNA sequence, making it possible to detect even small amounts of RNA or cDNA.

RT-PCR is a sensitive and specific technique that has many applications in medical research and diagnostics, including the detection of viruses such as HIV, hepatitis C virus, and SARS-CoV-2 (the virus that causes COVID-19). It can also be used to study gene expression, identify genetic mutations, and diagnose genetic disorders.

Recombinant fusion proteins are artificially created biomolecules that combine the functional domains or properties of two or more different proteins into a single protein entity. They are generated through recombinant DNA technology, where the genes encoding the desired protein domains are linked together and expressed as a single, chimeric gene in a host organism, such as bacteria, yeast, or mammalian cells.

The resulting fusion protein retains the functional properties of its individual constituent proteins, allowing for novel applications in research, diagnostics, and therapeutics. For instance, recombinant fusion proteins can be designed to enhance protein stability, solubility, or immunogenicity, making them valuable tools for studying protein-protein interactions, developing targeted therapies, or generating vaccines against infectious diseases or cancer.

Examples of recombinant fusion proteins include:

1. Etaglunatide (ABT-523): A soluble Fc fusion protein that combines the heavy chain fragment crystallizable region (Fc) of an immunoglobulin with the extracellular domain of the human interleukin-6 receptor (IL-6R). This fusion protein functions as a decoy receptor, neutralizing IL-6 and its downstream signaling pathways in rheumatoid arthritis.
2. Etanercept (Enbrel): A soluble TNF receptor p75 Fc fusion protein that binds to tumor necrosis factor-alpha (TNF-α) and inhibits its proinflammatory activity, making it a valuable therapeutic option for treating autoimmune diseases like rheumatoid arthritis, ankylosing spondylitis, and psoriasis.
3. Abatacept (Orencia): A fusion protein consisting of the extracellular domain of cytotoxic T-lymphocyte antigen 4 (CTLA-4) linked to the Fc region of an immunoglobulin, which downregulates T-cell activation and proliferation in autoimmune diseases like rheumatoid arthritis.
4. Belimumab (Benlysta): A monoclonal antibody that targets B-lymphocyte stimulator (BLyS) protein, preventing its interaction with the B-cell surface receptor and inhibiting B-cell activation in systemic lupus erythematosus (SLE).
5. Romiplostim (Nplate): A fusion protein consisting of a thrombopoietin receptor agonist peptide linked to an immunoglobulin Fc region, which stimulates platelet production in patients with chronic immune thrombocytopenia (ITP).
6. Darbepoetin alfa (Aranesp): A hyperglycosylated erythropoiesis-stimulating protein that functions as a longer-acting form of recombinant human erythropoietin, used to treat anemia in patients with chronic kidney disease or cancer.
7. Palivizumab (Synagis): A monoclonal antibody directed against the F protein of respiratory syncytial virus (RSV), which prevents RSV infection and is administered prophylactically to high-risk infants during the RSV season.
8. Ranibizumab (Lucentis): A recombinant humanized monoclonal antibody fragment that binds and inhibits vascular endothelial growth factor A (VEGF-A), used in the treatment of age-related macular degeneration, diabetic retinopathy, and other ocular disorders.
9. Cetuximab (Erbitux): A chimeric monoclonal antibody that binds to epidermal growth factor receptor (EGFR), used in the treatment of colorectal cancer and head and neck squamous cell carcinoma.
10. Adalimumab (Humira): A fully humanized monoclonal antibody that targets tumor necrosis factor-alpha (TNF-α), used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriasis, and Crohn's disease.
11. Bevacizumab (Avastin): A recombinant humanized monoclonal antibody that binds to VEGF-A, used in the treatment of various cancers, including colorectal, lung, breast, and kidney cancer.
12. Trastuzumab (Herceptin): A humanized monoclonal antibody that targets HER2/neu receptor, used in the treatment of breast cancer.
13. Rituximab (Rituxan): A chimeric monoclonal antibody that binds to CD20 antigen on B cells, used in the treatment of non-Hodgkin's lymphoma and rheumatoid arthritis.
14. Palivizumab (Synagis): A humanized monoclonal antibody that binds to the F protein of respiratory syncytial virus, used in the prevention of respiratory syncytial virus infection in high-risk infants.
15. Infliximab (Remicade): A chimeric monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis.
16. Natalizumab (Tysabri): A humanized monoclonal antibody that binds to α4β1 integrin, used in the treatment of multiple sclerosis and Crohn's disease.
17. Adalimumab (Humira): A fully human monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, and ulcerative colitis.
18. Golimumab (Simponi): A fully human monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis.
19. Certolizumab pegol (Cimzia): A PEGylated Fab' fragment of a humanized monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and Crohn's disease.
20. Ustekinumab (Stelara): A fully human monoclonal antibody that targets IL-12 and IL-23, used in the treatment of psoriasis, psoriatic arthritis, and Crohn's disease.
21. Secukinumab (Cosentyx): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis.
22. Ixekizumab (Taltz): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis and psoriatic arthritis.
23. Brodalumab (Siliq): A fully human monoclonal antibody that targets IL-17 receptor A, used in the treatment of psoriasis.
24. Sarilumab (Kevzara): A fully human monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis.
25. Tocilizumab (Actemra): A humanized monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis, and chimeric antigen receptor T-cell-induced cytokine release syndrome.
26. Siltuximab (Sylvant): A chimeric monoclonal antibody that targets IL-6, used in the treatment of multicentric Castleman disease.
27. Satralizumab (Enspryng): A humanized monoclonal antibody that targets IL-6 receptor alpha, used in the treatment of neuromyelitis optica spectrum disorder.
28. Sirukumab (Plivensia): A human monoclonal antibody that targets IL-6, used in the treatment

Oligonucleotide Array Sequence Analysis is a type of microarray analysis that allows for the simultaneous measurement of the expression levels of thousands of genes in a single sample. In this technique, oligonucleotides (short DNA sequences) are attached to a solid support, such as a glass slide, in a specific pattern. These oligonucleotides are designed to be complementary to specific target mRNA sequences from the sample being analyzed.

During the analysis, labeled RNA or cDNA from the sample is hybridized to the oligonucleotide array. The level of hybridization is then measured and used to determine the relative abundance of each target sequence in the sample. This information can be used to identify differences in gene expression between samples, which can help researchers understand the underlying biological processes involved in various diseases or developmental stages.

It's important to note that this technique requires specialized equipment and bioinformatics tools for data analysis, as well as careful experimental design and validation to ensure accurate and reproducible results.

I'm sorry for any confusion, but "Schizosaccharomyces pombe proteins" is not a medical term or concept. Schizosaccharomyces pombe is a type of single-celled microorganism called a yeast, which is often used as a model organism in scientific research. Proteins are complex molecules that do most of the work in cells and are necessary for the structure, function, and regulation of the body's tissues and organs.

In the context of scientific research, "Schizosaccharomyces pombe proteins" would refer to the specific proteins found in or studied using this particular type of yeast. These proteins may have similarities to human proteins and can be used to help understand basic biological processes, as well as diseases that occur in humans. However, it is important to note that while research using model organisms like Schizosaccharomyces pombe has led to many important discoveries, the findings may not always translate directly to humans.

A centrosome is a microtubule-organizing center found in animal cells. It consists of two barrel-shaped structures called centrioles, which are surrounded by a protein matrix called the pericentriolar material. The centrosome plays a crucial role in organizing the microtubules that form the cell's cytoskeleton and help to shape the cell, as well as in separating the chromosomes during cell division.

During mitosis, the two centrioles of the centrosome separate and move to opposite poles of the cell, where they nucleate the formation of the spindle fibers that pull the chromosomes apart. The centrosome also helps to ensure that the genetic material is equally distributed between the two resulting daughter cells.

It's worth noting that while centrioles are present in many animal cells, they are not always present in all types of cells. For example, plant cells do not have centrioles or centrosomes, and instead rely on other mechanisms to organize their microtubules.

Proto-oncogene proteins, such as c-Myc, are crucial regulators of normal cell growth, differentiation, and apoptosis (programmed cell death). When proto-oncogenes undergo mutations or alterations in their regulation, they can become overactive or overexpressed, leading to the formation of oncogenes. Oncogenic forms of c-Myc contribute to uncontrolled cell growth and division, which can ultimately result in cancer development.

The c-Myc protein is a transcription factor that binds to specific DNA sequences, influencing the expression of target genes involved in various cellular processes, such as:

1. Cell cycle progression: c-Myc promotes the expression of genes required for the G1 to S phase transition, driving cells into the DNA synthesis and division phase.
2. Metabolism: c-Myc regulates genes associated with glucose metabolism, glycolysis, and mitochondrial function, enhancing energy production in rapidly dividing cells.
3. Apoptosis: c-Myc can either promote or inhibit apoptosis, depending on the cellular context and the presence of other regulatory factors.
4. Differentiation: c-Myc generally inhibits differentiation by repressing genes that are necessary for specialized cell functions.
5. Angiogenesis: c-Myc can induce the expression of pro-angiogenic factors, promoting the formation of new blood vessels to support tumor growth.

Dysregulation of c-Myc is frequently observed in various types of cancer, making it an important therapeutic target for cancer treatment.

Nocodazole is not a medical condition or disease, but rather a pharmacological agent used in medical research and clinical settings. It's a synthetic chemical compound that belongs to the class of drugs known as microtubule inhibitors. Nocodazole works by binding to and disrupting the dynamic assembly and disassembly of microtubules, which are important components of the cell's cytoskeleton and play a critical role in cell division.

Nocodazole is primarily used in research settings as a tool for studying cell biology and mitosis, the process by which cells divide. It can be used to synchronize cells in the cell cycle or to induce mitotic arrest, making it useful for investigating various aspects of cell division and chromosome behavior.

In clinical settings, nocodazole has been used off-label as a component of some cancer treatment regimens, particularly in combination with other chemotherapeutic agents. Its ability to disrupt microtubules can interfere with the proliferation of cancer cells and enhance the effectiveness of certain anti-cancer drugs. However, its use is not widespread due to potential side effects and the availability of alternative treatments.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

3T3 cells are a type of cell line that is commonly used in scientific research. The name "3T3" is derived from the fact that these cells were developed by treating mouse embryo cells with a chemical called trypsin and then culturing them in a flask at a temperature of 37 degrees Celsius.

Specifically, 3T3 cells are a type of fibroblast, which is a type of cell that is responsible for producing connective tissue in the body. They are often used in studies involving cell growth and proliferation, as well as in toxicity tests and drug screening assays.

One particularly well-known use of 3T3 cells is in the 3T3-L1 cell line, which is a subtype of 3T3 cells that can be differentiated into adipocytes (fat cells) under certain conditions. These cells are often used in studies of adipose tissue biology and obesity.

It's important to note that because 3T3 cells are a type of immortalized cell line, they do not always behave exactly the same way as primary cells (cells that are taken directly from a living organism). As such, researchers must be careful when interpreting results obtained using 3T3 cells and consider any potential limitations or artifacts that may arise due to their use.

Cyclin A2 is a type of cyclin protein that regulates the cell cycle, which is the series of events that cells undergo as they grow and divide. Specifically, Cyclin A2 plays a role in the progression from the G1 phase to the S phase (DNA synthesis phase) and from the G2 phase to the M phase (mitosis phase) of the cell cycle. It does this by binding to and activating cyclin-dependent kinases (CDKs), which are enzymes that help regulate the cell cycle.

Cyclin A2 is expressed at various points during the cell cycle, but its levels peak during the S and G2 phases. The protein is degraded during mitosis, ensuring that it is not present in excess during the next cell cycle. Dysregulation of Cyclin A2 has been implicated in the development of cancer, as uncontrolled cell growth and division are hallmarks of this disease.

Fluorescence microscopy is a type of microscopy that uses fluorescent dyes or proteins to highlight and visualize specific components within a sample. In this technique, the sample is illuminated with high-energy light, typically ultraviolet (UV) or blue light, which excites the fluorescent molecules causing them to emit lower-energy, longer-wavelength light, usually visible light in the form of various colors. This emitted light is then collected by the microscope and detected to produce an image.

Fluorescence microscopy has several advantages over traditional brightfield microscopy, including the ability to visualize specific structures or molecules within a complex sample, increased sensitivity, and the potential for quantitative analysis. It is widely used in various fields of biology and medicine, such as cell biology, neuroscience, and pathology, to study the structure, function, and interactions of cells and proteins.

There are several types of fluorescence microscopy techniques, including widefield fluorescence microscopy, confocal microscopy, two-photon microscopy, and total internal reflection fluorescence (TIRF) microscopy, each with its own strengths and limitations. These techniques can provide valuable insights into the behavior of cells and proteins in health and disease.

CDC28 protein kinase in Saccharomyces cerevisiae (Baker's yeast) is a crucial cell cycle regulator, specifically a cyclin-dependent kinase (CDK). It plays a pivotal role in controlling the G1 to S phase transition during the cell division cycle. CDC28 forms complexes with various cyclins, such as G1 cyclins CLN1, CLN2, and CLN3, and S phase cyclin CLB5, to regulate different stages of the cell cycle. The activity of CDC28 is tightly controlled through phosphorylation, dephosphorylation, and proteolysis of the cyclin subunits. Inhibition or mutation of CDC28 can lead to cell cycle arrest and various developmental defects in yeast.

A phenotype is the physical or biochemical expression of an organism's genes, or the observable traits and characteristics resulting from the interaction of its genetic constitution (genotype) with environmental factors. These characteristics can include appearance, development, behavior, and resistance to disease, among others. Phenotypes can vary widely, even among individuals with identical genotypes, due to differences in environmental influences, gene expression, and genetic interactions.

Repressor proteins are a type of regulatory protein in molecular biology that suppress the transcription of specific genes into messenger RNA (mRNA) by binding to DNA. They function as part of gene regulation processes, often working in conjunction with an operator region and a promoter region within the DNA molecule. Repressor proteins can be activated or deactivated by various signals, allowing for precise control over gene expression in response to changing cellular conditions.

There are two main types of repressor proteins:

1. DNA-binding repressors: These directly bind to specific DNA sequences (operator regions) near the target gene and prevent RNA polymerase from transcribing the gene into mRNA.
2. Allosteric repressors: These bind to effector molecules, which then cause a conformational change in the repressor protein, enabling it to bind to DNA and inhibit transcription.

Repressor proteins play crucial roles in various biological processes, such as development, metabolism, and stress response, by controlling gene expression patterns in cells.

Gene expression regulation in fungi refers to the complex cellular processes that control the production of proteins and other functional gene products in response to various internal and external stimuli. This regulation is crucial for normal growth, development, and adaptation of fungal cells to changing environmental conditions.

In fungi, gene expression is regulated at multiple levels, including transcriptional, post-transcriptional, translational, and post-translational modifications. Key regulatory mechanisms include:

1. Transcription factors (TFs): These proteins bind to specific DNA sequences in the promoter regions of target genes and either activate or repress their transcription. Fungi have a diverse array of TFs that respond to various signals, such as nutrient availability, stress, developmental cues, and quorum sensing.
2. Chromatin remodeling: The organization and compaction of DNA into chromatin can influence gene expression. Fungi utilize ATP-dependent chromatin remodeling complexes and histone modifying enzymes to alter chromatin structure, thereby facilitating or inhibiting the access of transcriptional machinery to genes.
3. Non-coding RNAs: Small non-coding RNAs (sncRNAs) play a role in post-transcriptional regulation of gene expression in fungi. These sncRNAs can guide RNA-induced transcriptional silencing (RITS) complexes to specific target loci, leading to the repression of gene expression through histone modifications and DNA methylation.
4. Alternative splicing: Fungi employ alternative splicing mechanisms to generate multiple mRNA isoforms from a single gene, thereby increasing proteome diversity. This process can be regulated by RNA-binding proteins that recognize specific sequence motifs in pre-mRNAs and promote or inhibit splicing events.
5. Protein stability and activity: Post-translational modifications (PTMs) of proteins, such as phosphorylation, ubiquitination, and sumoylation, can influence their stability, localization, and activity. These PTMs play a crucial role in regulating various cellular processes, including signal transduction, stress response, and cell cycle progression.

Understanding the complex interplay between these regulatory mechanisms is essential for elucidating the molecular basis of fungal development, pathogenesis, and drug resistance. This knowledge can be harnessed to develop novel strategies for combating fungal infections and improving agricultural productivity.

Ataxia telangiectasia mutated (ATM) proteins are a type of protein that play a crucial role in the maintenance and repair of DNA in cells. The ATM gene produces these proteins, which are involved in several important cellular processes such as:

1. DNA damage response: When DNA is damaged, ATM proteins help to detect and respond to the damage by activating various signaling pathways that lead to DNA repair or apoptosis (programmed cell death) if the damage is too severe.
2. Cell cycle regulation: ATM proteins regulate the cell cycle by controlling checkpoints that ensure proper DNA replication and division. This helps prevent the propagation of cells with damaged DNA.
3. Telomere maintenance: ATM proteins help maintain telomeres, which are the protective caps at the ends of chromosomes. Telomeres shorten as cells divide, and when they become too short, cells can no longer divide and enter a state of senescence or die.

Mutations in the ATM gene can lead to Ataxia-telangiectasia (A-T), a rare inherited disorder characterized by neurological problems, immune system dysfunction, increased risk of cancer, and sensitivity to ionizing radiation. People with A-T have defective ATM proteins that cannot properly respond to DNA damage, leading to genomic instability and increased susceptibility to disease.

Checkpoint Kinase 2 (Chk2) is a serine/threonine protein kinase that plays a crucial role in the DNA damage response and the regulation of the cell cycle. It is activated by various types of DNA damage, including double-strand breaks, and phosphorylates several downstream targets involved in cell cycle arrest, DNA repair, and apoptosis. Chk2 is a key player in the G2/M checkpoint, which prevents cells with damaged DNA from entering mitosis and dividing. Mutations in the Chk2 gene have been associated with increased risk of cancer.

Enzyme activation refers to the process by which an enzyme becomes biologically active and capable of carrying out its specific chemical or biological reaction. This is often achieved through various post-translational modifications, such as proteolytic cleavage, phosphorylation, or addition of cofactors or prosthetic groups to the enzyme molecule. These modifications can change the conformation or structure of the enzyme, exposing or creating a binding site for the substrate and allowing the enzymatic reaction to occur.

For example, in the case of proteolytic cleavage, an inactive precursor enzyme, known as a zymogen, is cleaved into its active form by a specific protease. This is seen in enzymes such as trypsin and chymotrypsin, which are initially produced in the pancreas as inactive precursors called trypsinogen and chymotrypsinogen, respectively. Once they reach the small intestine, they are activated by enteropeptidase, a protease that cleaves a specific peptide bond, releasing the active enzyme.

Phosphorylation is another common mechanism of enzyme activation, where a phosphate group is added to a specific serine, threonine, or tyrosine residue on the enzyme by a protein kinase. This modification can alter the conformation of the enzyme and create a binding site for the substrate, allowing the enzymatic reaction to occur.

Enzyme activation is a crucial process in many biological pathways, as it allows for precise control over when and where specific reactions take place. It also provides a mechanism for regulating enzyme activity in response to various signals and stimuli, such as hormones, neurotransmitters, or changes in the intracellular environment.

Developmental gene expression regulation refers to the processes that control the activation or repression of specific genes during embryonic and fetal development. These regulatory mechanisms ensure that genes are expressed at the right time, in the right cells, and at appropriate levels to guide proper growth, differentiation, and morphogenesis of an organism.

Developmental gene expression regulation is a complex and dynamic process involving various molecular players, such as transcription factors, chromatin modifiers, non-coding RNAs, and signaling molecules. These regulators can interact with cis-regulatory elements, like enhancers and promoters, to fine-tune the spatiotemporal patterns of gene expression during development.

Dysregulation of developmental gene expression can lead to various congenital disorders and developmental abnormalities. Therefore, understanding the principles and mechanisms governing developmental gene expression regulation is crucial for uncovering the etiology of developmental diseases and devising potential therapeutic strategies.

Caulobacter is a genus of gram-negative, aerobic, aquatic bacteria that are characterized by the presence of a polar stalk or attachment structure. These bacteria are commonly found in freshwater and marine environments and play an important role in organic matter decomposition and nutrient cycling. The stalk of Caulobacter contains adhesins that allow the bacterium to attach to surfaces, while the unstalked portion can move using flagella.

Caulobacter has a complex life cycle involving two distinct cell types: a swarmer cell and a stalked cell. Swarmer cells are motile and have a single polar flagellum that they use to search for new surfaces to attach to. Once they find a suitable surface, they differentiate into stalked cells by synthesizing a stalk structure at the site of attachment. The stalked cells then replicate their DNA and divide asymmetrically to produce a new swarmer cell and a new stalked cell.

Caulobacter is an important model organism for studying bacterial cell differentiation, motility, and surface adhesion. It has also been studied as a potential source of novel enzymes and bioactive compounds with applications in biotechnology and medicine.

Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.

Fungal genes refer to the genetic material present in fungi, which are eukaryotic organisms that include microorganisms such as yeasts and molds, as well as larger organisms like mushrooms. The genetic material of fungi is composed of DNA, just like in other eukaryotes, and is organized into chromosomes located in the nucleus of the cell.

Fungal genes are segments of DNA that contain the information necessary to produce proteins and RNA molecules required for various cellular functions. These genes are transcribed into messenger RNA (mRNA) molecules, which are then translated into proteins by ribosomes in the cytoplasm.

Fungal genomes have been sequenced for many species, revealing a diverse range of genes that encode proteins involved in various cellular processes such as metabolism, signaling, and regulation. Comparative genomic analyses have also provided insights into the evolutionary relationships among different fungal lineages and have helped to identify unique genetic features that distinguish fungi from other eukaryotes.

Understanding fungal genes and their functions is essential for advancing our knowledge of fungal biology, as well as for developing new strategies to control fungal pathogens that can cause diseases in humans, animals, and plants.

Chromatin is the complex of DNA, RNA, and proteins that make up the chromosomes in the nucleus of a cell. It is responsible for packaging the long DNA molecules into a more compact form that fits within the nucleus. Chromatin is made up of repeating units called nucleosomes, which consist of a histone protein octamer wrapped tightly by DNA. The structure of chromatin can be altered through chemical modifications to the histone proteins and DNA, which can influence gene expression and other cellular processes.

S-phase kinase-associated proteins (Skp2) are a group of proteins that are associated with the S-phase kinase, which is a type of enzyme that helps to regulate the cell cycle. Specifically, Skp2 is involved in the ubiquitination and degradation of certain proteins that play a role in controlling the progression of the cell cycle.

Skp2 is a member of the F-box protein family, which are components of the Skp1-Cul1-F-box (SCF) complex, a type of E3 ubiquitin ligase. The SCF complex recognizes and binds to specific proteins, tagging them for ubiquitination and subsequent degradation by the proteasome.

One of the key targets of Skp2 is the tumor suppressor protein p27, which inhibits the activity of cyclin-dependent kinases (CDKs) and helps to regulate the transition from the G1 phase to the S phase of the cell cycle. By targeting p27 for degradation, Skp2 promotes the progression of the cell cycle and has been implicated in the development of various types of cancer.

Overall, Skp2 plays a critical role in regulating the cell cycle and has important implications for the development and treatment of various diseases, including cancer.

Up-regulation is a term used in molecular biology and medicine to describe an increase in the expression or activity of a gene, protein, or receptor in response to a stimulus. This can occur through various mechanisms such as increased transcription, translation, or reduced degradation of the molecule. Up-regulation can have important functional consequences, for example, enhancing the sensitivity or response of a cell to a hormone, neurotransmitter, or drug. It is a normal physiological process that can also be induced by disease or pharmacological interventions.

Cellular aging, also known as cellular senescence, is a natural process that occurs as cells divide and grow older. Over time, cells accumulate damage to their DNA, proteins, and lipids due to various factors such as genetic mutations, oxidative stress, and epigenetic changes. This damage can impair the cell's ability to function properly and can lead to changes associated with aging, such as decreased tissue repair and regeneration, increased inflammation, and increased risk of age-related diseases.

Cellular aging is characterized by several features, including:

1. Shortened telomeres: Telomeres are the protective caps on the ends of chromosomes that shorten each time a cell divides. When telomeres become too short, the cell can no longer divide and becomes senescent or dies.
2. Epigenetic changes: Epigenetic modifications refer to chemical changes to DNA and histone proteins that affect gene expression without changing the underlying genetic code. As cells age, they accumulate epigenetic changes that can alter gene expression and contribute to cellular aging.
3. Oxidative stress: Reactive oxygen species (ROS) are byproducts of cellular metabolism that can damage DNA, proteins, and lipids. Accumulated ROS over time can lead to oxidative stress, which is associated with cellular aging.
4. Inflammation: Senescent cells produce pro-inflammatory cytokines, chemokines, and matrix metalloproteinases that contribute to a low-grade inflammation known as inflammaging. This chronic inflammation can lead to tissue damage and increase the risk of age-related diseases.
5. Genomic instability: DNA damage accumulates with age, leading to genomic instability and an increased risk of mutations and cancer.

Understanding cellular aging is crucial for developing interventions that can delay or prevent age-related diseases and improve healthy lifespan.

Gamma rays are a type of ionizing radiation that is released from the nucleus of an atom during radioactive decay. They are high-energy photons, with wavelengths shorter than 0.01 nanometers and frequencies greater than 3 x 10^19 Hz. Gamma rays are electromagnetic radiation, similar to X-rays, but with higher energy levels and the ability to penetrate matter more deeply. They can cause damage to living tissue and are used in medical imaging and cancer treatment.

DNA primers are short single-stranded DNA molecules that serve as a starting point for DNA synthesis. They are typically used in laboratory techniques such as the polymerase chain reaction (PCR) and DNA sequencing. The primer binds to a complementary sequence on the DNA template through base pairing, providing a free 3'-hydroxyl group for the DNA polymerase enzyme to add nucleotides and synthesize a new strand of DNA. This allows for specific and targeted amplification or analysis of a particular region of interest within a larger DNA molecule.

Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.

Sequence homology, amino acid, refers to the similarity in the order of amino acids in a protein or a portion of a protein between two or more species. This similarity can be used to infer evolutionary relationships and functional similarities between proteins. The higher the degree of sequence homology, the more likely it is that the proteins are related and have similar functions. Sequence homology can be determined through various methods such as pairwise alignment or multiple sequence alignment, which compare the sequences and calculate a score based on the number and type of matching amino acids.

Thymidine is a pyrimidine nucleoside that consists of a thymine base linked to a deoxyribose sugar by a β-N1-glycosidic bond. It plays a crucial role in DNA replication and repair processes as one of the four nucleosides in DNA, along with adenosine, guanosine, and cytidine. Thymidine is also used in research and clinical settings for various purposes, such as studying DNA synthesis or as a component of antiviral and anticancer therapies.

A neoplasm is a tumor or growth that is formed by an abnormal and excessive proliferation of cells, which can be benign or malignant. Neoplasm proteins are therefore any proteins that are expressed or produced in these neoplastic cells. These proteins can play various roles in the development, progression, and maintenance of neoplasms.

Some neoplasm proteins may contribute to the uncontrolled cell growth and division seen in cancer, such as oncogenic proteins that promote cell cycle progression or inhibit apoptosis (programmed cell death). Others may help the neoplastic cells evade the immune system, allowing them to proliferate undetected. Still others may be involved in angiogenesis, the formation of new blood vessels that supply the tumor with nutrients and oxygen.

Neoplasm proteins can also serve as biomarkers for cancer diagnosis, prognosis, or treatment response. For example, the presence or level of certain neoplasm proteins in biological samples such as blood or tissue may indicate the presence of a specific type of cancer, help predict the likelihood of cancer recurrence, or suggest whether a particular therapy will be effective.

Overall, understanding the roles and behaviors of neoplasm proteins can provide valuable insights into the biology of cancer and inform the development of new diagnostic and therapeutic strategies.

Aphidicolin is an antimicrotubule agent that is specifically a inhibitor of DNA polymerase alpha. It is an antibiotic that is produced by the fungus Cephalosporium aphidicola and is used in research to study the cell cycle and DNA replication. In clinical medicine, it has been explored as a potential anticancer agent, although its use is not currently approved for this indication.

Neoplastic cell transformation is a process in which a normal cell undergoes genetic alterations that cause it to become cancerous or malignant. This process involves changes in the cell's DNA that result in uncontrolled cell growth and division, loss of contact inhibition, and the ability to invade surrounding tissues and metastasize (spread) to other parts of the body.

Neoplastic transformation can occur as a result of various factors, including genetic mutations, exposure to carcinogens, viral infections, chronic inflammation, and aging. These changes can lead to the activation of oncogenes or the inactivation of tumor suppressor genes, which regulate cell growth and division.

The transformation of normal cells into cancerous cells is a complex and multi-step process that involves multiple genetic and epigenetic alterations. It is characterized by several hallmarks, including sustained proliferative signaling, evasion of growth suppressors, resistance to cell death, enabling replicative immortality, induction of angiogenesis, activation of invasion and metastasis, reprogramming of energy metabolism, and evading immune destruction.

Neoplastic cell transformation is a fundamental concept in cancer biology and is critical for understanding the molecular mechanisms underlying cancer development and progression. It also has important implications for cancer diagnosis, prognosis, and treatment, as identifying the specific genetic alterations that underlie neoplastic transformation can help guide targeted therapies and personalized medicine approaches.

Cyclin-dependent kinase inhibitor p57, also known as CDKN1C or p57KIP2, is a protein that regulates the cell cycle and acts as a tumor suppressor. It inhibits the activity of cyclin-dependent kinases (CDKs), which are enzymes that play crucial roles in regulating the cell cycle and transitioning from one phase to another.

The p57 protein is encoded by the CDKN1C gene, which is located on chromosome 11p15.5. This region is known as an imprinted gene cluster, meaning that only one copy of the gene is active, depending on whether it is inherited from the mother or father. In the case of p57, the paternal allele is usually silenced, and only the maternal allele is expressed.

Mutations in the CDKN1C gene can lead to several developmental disorders, including Beckwith-Wiedemann syndrome (BWS), a condition characterized by overgrowth, abdominal wall defects, and an increased risk of childhood tumors. Loss of function mutations in CDKN1C have also been associated with an increased risk of cancer, particularly Wilms' tumor, a type of kidney cancer that typically affects children.

In summary, cyclin-dependent kinase inhibitor p57 is a protein that regulates the cell cycle and acts as a tumor suppressor by inhibiting the activity of CDKs. Mutations in the CDKN1C gene can lead to developmental disorders and an increased risk of cancer.

Microtubules are hollow, cylindrical structures composed of tubulin proteins in the cytoskeleton of eukaryotic cells. They play crucial roles in various cellular processes such as maintaining cell shape, intracellular transport, and cell division (mitosis and meiosis). Microtubules are dynamic, undergoing continuous assembly and disassembly, which allows them to rapidly reorganize in response to cellular needs. They also form part of important cellular structures like centrioles, basal bodies, and cilia/flagella.

Cytoplasm is the material within a eukaryotic cell (a cell with a true nucleus) that lies between the nuclear membrane and the cell membrane. It is composed of an aqueous solution called cytosol, in which various organelles such as mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles are suspended. Cytoplasm also contains a variety of dissolved nutrients, metabolites, ions, and enzymes that are involved in various cellular processes such as metabolism, signaling, and transport. It is where most of the cell's metabolic activities take place, and it plays a crucial role in maintaining the structure and function of the cell.

Retinoblastoma-like protein p107, also known as RBL1 or p107, is a tumor suppressor protein that belongs to the family of "pocket proteins." This protein is encoded by the RBL1 gene in humans. It plays a crucial role in regulating the cell cycle and preventing uncontrolled cell growth, which can lead to cancer.

The p107 protein is structurally similar to the retinoblastoma protein (pRb) and functions in a related manner. Both proteins interact with E2F transcription factors to control the expression of genes required for DNA replication and cell division. When the p107 protein is phosphorylated by cyclin-dependent kinases during the G1 phase of the cell cycle, it releases E2F transcription factors, allowing them to activate the transcription of target genes necessary for S phase entry and DNA replication.

Retinoblastoma-like protein p107 is often inactivated or mutated in various human cancers, including retinoblastoma, small cell lung cancer, and certain types of sarcomas. Loss of p107 function can lead to uncontrolled cell growth and tumor formation. However, it's important to note that the role of p107 in cancer development is complex and may depend on its interactions with other proteins and signaling pathways.

Neoplasms are abnormal growths of cells or tissues in the body that serve no physiological function. They can be benign (non-cancerous) or malignant (cancerous). Benign neoplasms are typically slow growing and do not spread to other parts of the body, while malignant neoplasms are aggressive, invasive, and can metastasize to distant sites.

Neoplasms occur when there is a dysregulation in the normal process of cell division and differentiation, leading to uncontrolled growth and accumulation of cells. This can result from genetic mutations or other factors such as viral infections, environmental exposures, or hormonal imbalances.

Neoplasms can develop in any organ or tissue of the body and can cause various symptoms depending on their size, location, and type. Treatment options for neoplasms include surgery, radiation therapy, chemotherapy, immunotherapy, and targeted therapy, among others.

Antineoplastic agents, phytogenic, also known as plant-derived anticancer drugs, are medications that are derived from plants and used to treat cancer. These agents have natural origins and work by interfering with the growth and multiplication of cancer cells, helping to slow or stop the spread of the disease. Some examples of antineoplastic agents, phytogenic include paclitaxel (Taxol), vincristine, vinblastine, and etoposide. These drugs are often used in combination with other treatments such as surgery, radiation therapy, and other medications to provide a comprehensive approach to cancer care.

Breast neoplasms refer to abnormal growths in the breast tissue that can be benign or malignant. Benign breast neoplasms are non-cancerous tumors or growths, while malignant breast neoplasms are cancerous tumors that can invade surrounding tissues and spread to other parts of the body.

Breast neoplasms can arise from different types of cells in the breast, including milk ducts, milk sacs (lobules), or connective tissue. The most common type of breast cancer is ductal carcinoma, which starts in the milk ducts and can spread to other parts of the breast and nearby structures.

Breast neoplasms are usually detected through screening methods such as mammography, ultrasound, or MRI, or through self-examination or clinical examination. Treatment options for breast neoplasms depend on several factors, including the type and stage of the tumor, the patient's age and overall health, and personal preferences. Treatment may include surgery, radiation therapy, chemotherapy, hormone therapy, or targeted therapy.

Retinoblastoma-like protein p130, also known as RBL2 or p130, is a tumor suppressor protein that belongs to the family of retinoblastoma proteins (pRb, p107, and p130). It is encoded by the RBL2 gene located on chromosome 12q13. This protein plays crucial roles in regulating the cell cycle, differentiation, and apoptosis.

The primary function of p130 is to negatively control the transition from the G1 phase to the S phase of the cell cycle. It does so by forming a complex with E2F4 or E2F5 transcription factors, which results in the repression of genes required for DNA replication and cell cycle progression. The activity of p130 is regulated through phosphorylation by cyclin-dependent kinases (CDKs) during the cell cycle. When p130 is hypophosphorylated, it can bind to E2F4/E2F5 and repress target gene transcription; however, when p130 gets phosphorylated by CDKs, it releases from E2F4/E2F5, leading to the activation of cell cycle-promoting genes.

Retinoblastoma-like protein p130 is often inactivated or downregulated in various human cancers, including retinoblastoma, lung cancer, breast cancer, and others. This loss of function contributes to uncontrolled cell growth and tumorigenesis. Therefore, understanding the role of p130 in cell cycle regulation and its dysfunction in cancer provides valuable insights into potential therapeutic targets for cancer treatment.

Proto-oncogene proteins c-bcl-2 are a group of proteins that play a role in regulating cell death (apoptosis). The c-bcl-2 gene produces one of these proteins, which helps to prevent cells from undergoing apoptosis. This protein is located on the membrane of mitochondria and endoplasmic reticulum and it can inhibit the release of cytochrome c, a key player in the activation of caspases, which are enzymes that trigger apoptosis.

In normal cells, the regulation of c-bcl-2 protein helps to maintain a balance between cell proliferation and cell death, ensuring proper tissue homeostasis. However, when the c-bcl-2 gene is mutated or its expression is dysregulated, it can contribute to cancer development by allowing cancer cells to survive and proliferate. High levels of c-bcl-2 protein have been found in many types of cancer, including leukemia, lymphoma, and carcinomas, and are often associated with a poor prognosis.

Meiosis is a type of cell division that results in the formation of four daughter cells, each with half the number of chromosomes as the parent cell. It is a key process in sexual reproduction, where it generates gametes or sex cells (sperm and eggs).

The process of meiosis involves one round of DNA replication followed by two successive nuclear divisions, meiosis I and meiosis II. In meiosis I, homologous chromosomes pair, form chiasma and exchange genetic material through crossing over, then separate from each other. In meiosis II, sister chromatids separate, leading to the formation of four haploid cells. This process ensures genetic diversity in offspring by shuffling and recombining genetic information during the formation of gametes.

Intracellular signaling peptides and proteins are molecules that play a crucial role in transmitting signals within cells, which ultimately lead to changes in cell behavior or function. These signals can originate from outside the cell (extracellular) or within the cell itself. Intracellular signaling molecules include various types of peptides and proteins, such as:

1. G-protein coupled receptors (GPCRs): These are seven-transmembrane domain receptors that bind to extracellular signaling molecules like hormones, neurotransmitters, or chemokines. Upon activation, they initiate a cascade of intracellular signals through G proteins and secondary messengers.
2. Receptor tyrosine kinases (RTKs): These are transmembrane receptors that bind to growth factors, cytokines, or hormones. Activation of RTKs leads to autophosphorylation of specific tyrosine residues, creating binding sites for intracellular signaling proteins such as adapter proteins, phosphatases, and enzymes like Ras, PI3K, and Src family kinases.
3. Second messenger systems: Intracellular second messengers are small molecules that amplify and propagate signals within the cell. Examples include cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), diacylglycerol (DAG), inositol triphosphate (IP3), calcium ions (Ca2+), and nitric oxide (NO). These second messengers activate or inhibit various downstream effectors, leading to changes in cellular responses.
4. Signal transduction cascades: Intracellular signaling proteins often form complex networks of interacting molecules that relay signals from the plasma membrane to the nucleus. These cascades involve kinases (protein kinases A, B, C, etc.), phosphatases, and adapter proteins, which ultimately regulate gene expression, cell cycle progression, metabolism, and other cellular processes.
5. Ubiquitination and proteasome degradation: Intracellular signaling pathways can also control protein stability by modulating ubiquitin-proteasome degradation. E3 ubiquitin ligases recognize specific substrates and conjugate them with ubiquitin molecules, targeting them for proteasomal degradation. This process regulates the abundance of key signaling proteins and contributes to signal termination or amplification.

In summary, intracellular signaling pathways involve a complex network of interacting proteins that relay signals from the plasma membrane to various cellular compartments, ultimately regulating gene expression, metabolism, and other cellular processes. Dysregulation of these pathways can contribute to disease development and progression, making them attractive targets for therapeutic intervention.

Cell death is the process by which cells cease to function and eventually die. There are several ways that cells can die, but the two most well-known and well-studied forms of cell death are apoptosis and necrosis.

Apoptosis is a programmed form of cell death that occurs as a normal and necessary process in the development and maintenance of healthy tissues. During apoptosis, the cell's DNA is broken down into small fragments, the cell shrinks, and the membrane around the cell becomes fragmented, allowing the cell to be easily removed by phagocytic cells without causing an inflammatory response.

Necrosis, on the other hand, is a form of cell death that occurs as a result of acute tissue injury or overwhelming stress. During necrosis, the cell's membrane becomes damaged and the contents of the cell are released into the surrounding tissue, causing an inflammatory response.

There are also other forms of cell death, such as autophagy, which is a process by which cells break down their own organelles and proteins to recycle nutrients and maintain energy homeostasis, and pyroptosis, which is a form of programmed cell death that occurs in response to infection and involves the activation of inflammatory caspases.

Cell death is an important process in many physiological and pathological processes, including development, tissue homeostasis, and disease. Dysregulation of cell death can contribute to the development of various diseases, including cancer, neurodegenerative disorders, and autoimmune diseases.

Cyclin G is a type of protein that belongs to the cyclin family, which are involved in the regulation of the cell cycle. The human Cyclin G gene encodes two isoforms, Cyclin G1 and Cyclin G2, which share a similar structure but have different functions.

Cyclin G1 is known to play a role in the negative regulation of the cell cycle, particularly during the G1 phase. It interacts with several proteins, including CDKs (cyclin-dependent kinases), to regulate the activity of various transcription factors and other signaling pathways that control cell growth and division.

Cyclin G2, on the other hand, has been implicated in the regulation of DNA damage response and apoptosis (programmed cell death). It interacts with CDKs and other proteins to modulate the activity of various signaling pathways involved in these processes.

Overall, Cyclin G plays important roles in regulating cell cycle progression, DNA damage response, and apoptosis, and its dysregulation has been linked to several human diseases, including cancer.

Immunoblotting, also known as western blotting, is a laboratory technique used in molecular biology and immunogenetics to detect and quantify specific proteins in a complex mixture. This technique combines the electrophoretic separation of proteins by gel electrophoresis with their detection using antibodies that recognize specific epitopes (protein fragments) on the target protein.

The process involves several steps: first, the protein sample is separated based on size through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Next, the separated proteins are transferred onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric field. The membrane is then blocked with a blocking agent to prevent non-specific binding of antibodies.

After blocking, the membrane is incubated with a primary antibody that specifically recognizes the target protein. Following this, the membrane is washed to remove unbound primary antibodies and then incubated with a secondary antibody conjugated to an enzyme such as horseradish peroxidase (HRP) or alkaline phosphatase (AP). The enzyme catalyzes a colorimetric or chemiluminescent reaction that allows for the detection of the target protein.

Immunoblotting is widely used in research and clinical settings to study protein expression, post-translational modifications, protein-protein interactions, and disease biomarkers. It provides high specificity and sensitivity, making it a valuable tool for identifying and quantifying proteins in various biological samples.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Growth inhibitors, in a medical context, refer to substances or agents that reduce or prevent the growth and proliferation of cells. They play an essential role in regulating normal cellular growth and can be used in medical treatments to control the excessive growth of unwanted cells, such as cancer cells.

There are two main types of growth inhibitors:

1. Endogenous growth inhibitors: These are naturally occurring molecules within the body that help regulate cell growth and division. Examples include retinoids, which are vitamin A derivatives, and interferons, which are signaling proteins released by host cells in response to viruses.

2. Exogenous growth inhibitors: These are synthetic or natural substances from outside the body that can be used to inhibit cell growth. Many chemotherapeutic agents and targeted therapies for cancer treatment fall into this category. They work by interfering with specific pathways involved in cell division, such as DNA replication or mitosis, or by inducing apoptosis (programmed cell death) in cancer cells.

It is important to note that growth inhibitors may also affect normal cells, which can lead to side effects during treatment. The challenge for medical researchers is to develop targeted therapies that specifically inhibit the growth of abnormal cells while minimizing harm to healthy cells.

p53 is a tumor suppressor gene that encodes a protein responsible for controlling cell growth and division. The p53 protein plays a crucial role in preventing the development of cancer by regulating the cell cycle and activating DNA repair processes when genetic damage is detected. If the damage is too severe to be repaired, p53 can trigger apoptosis, or programmed cell death, to prevent the propagation of potentially cancerous cells. Mutations in the TP53 gene, which encodes the p53 protein, are among the most common genetic alterations found in human cancers and are often associated with a poor prognosis.

According to the medical definition, ultraviolet (UV) rays are invisible radiations that fall in the range of the electromagnetic spectrum between 100-400 nanometers. UV rays are further divided into three categories: UVA (320-400 nm), UVB (280-320 nm), and UVC (100-280 nm).

UV rays have various sources, including the sun and artificial sources like tanning beds. Prolonged exposure to UV rays can cause damage to the skin, leading to premature aging, eye damage, and an increased risk of skin cancer. UVA rays penetrate deeper into the skin and are associated with skin aging, while UVB rays primarily affect the outer layer of the skin and are linked to sunburns and skin cancer. UVC rays are the most harmful but fortunately, they are absorbed by the Earth's atmosphere and do not reach the surface.

Healthcare professionals recommend limiting exposure to UV rays, wearing protective clothing, using broad-spectrum sunscreen with an SPF of at least 30, and avoiding tanning beds to reduce the risk of UV-related health problems.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

HCT116 cells are a type of human colon cancer cell line that is widely used in scientific research. They were originally established in the early 1980s from a primary colon tumor that had metastasized to the liver. HCT116 cells are known for their stability, robust growth, and susceptibility to various genetic manipulations, making them a popular choice for studying cancer biology, drug discovery, and gene function.

These cells have several important features that make them useful in research. For example, they harbor mutations in key genes involved in colorectal cancer development, such as the adenomatous polyposis coli (APC) gene and the KRAS oncogene. Additionally, HCT116 cells can be easily cultured in the lab and are amenable to a variety of experimental techniques, including genetic modification, drug screening, and protein analysis.

It is important to note that while HCT116 cells provide valuable insights into colon cancer biology, they represent only one type of cancer cell line, and their behavior may not necessarily reflect the complexity of human tumors in vivo. Therefore, researchers must exercise caution when interpreting results obtained from these cells and consider other complementary approaches to validate their findings.

Trans-activators are proteins that increase the transcriptional activity of a gene or a set of genes. They do this by binding to specific DNA sequences and interacting with the transcription machinery, thereby enhancing the recruitment and assembly of the complexes needed for transcription. In some cases, trans-activators can also modulate the chromatin structure to make the template more accessible to the transcription machinery.

In the context of HIV (Human Immunodeficiency Virus) infection, the term "trans-activator" is often used specifically to refer to the Tat protein. The Tat protein is a viral regulatory protein that plays a critical role in the replication of HIV by activating the transcription of the viral genome. It does this by binding to a specific RNA structure called the Trans-Activation Response Element (TAR) located at the 5' end of all nascent HIV transcripts, and recruiting cellular cofactors that enhance the processivity and efficiency of RNA polymerase II, leading to increased viral gene expression.

The proteasome endopeptidase complex is a large protein complex found in the cells of eukaryotic organisms, as well as in archaea and some bacteria. It plays a crucial role in the degradation of damaged or unneeded proteins through a process called proteolysis. The proteasome complex contains multiple subunits, including both regulatory and catalytic particles.

The catalytic core of the proteasome is composed of four stacked rings, each containing seven subunits, forming a structure known as the 20S core particle. Three of these rings are made up of beta-subunits that contain the proteolytic active sites, while the fourth ring consists of alpha-subunits that control access to the interior of the complex.

The regulatory particles, called 19S or 11S regulators, cap the ends of the 20S core particle and are responsible for recognizing, unfolding, and translocating targeted proteins into the catalytic chamber. The proteasome endopeptidase complex can cleave peptide bonds in various ways, including hydrolysis of ubiquitinated proteins, which is an essential mechanism for maintaining protein quality control and regulating numerous cellular processes, such as cell cycle progression, signal transduction, and stress response.

In summary, the proteasome endopeptidase complex is a crucial intracellular machinery responsible for targeted protein degradation through proteolysis, contributing to various essential regulatory functions in cells.

Tubulin is a type of protein that forms microtubules, which are hollow cylindrical structures involved in the cell's cytoskeleton. These structures play important roles in various cellular processes, including maintaining cell shape, cell division, and intracellular transport. There are two main types of tubulin proteins: alpha-tubulin and beta-tubulin. They polymerize to form heterodimers, which then assemble into microtubules. The assembly and disassembly of microtubules are dynamic processes that are regulated by various factors, including GTP hydrolysis, motor proteins, and microtubule-associated proteins (MAPs). Tubulin is an essential component of the eukaryotic cell and has been a target for anti-cancer drugs such as taxanes and vinca alkaloids.

Kinetin is a type of plant growth hormone, specifically a cytokinin. It plays a crucial role in cell division and differentiation, as well as promoting growth and delaying senescence (aging) in plants. Kinetin has also been studied for its potential use in various medical applications, including wound healing, tissue culture, and skin care products. However, it is primarily known for its role in plant biology.

According to the National Institutes of Health (NIH), stem cells are "initial cells" or "precursor cells" that have the ability to differentiate into many different cell types in the body. They can also divide without limit to replenish other cells for as long as the person or animal is still alive.

There are two main types of stem cells: embryonic stem cells, which come from human embryos, and adult stem cells, which are found in various tissues throughout the body. Embryonic stem cells have the ability to differentiate into all cell types in the body, while adult stem cells have more limited differentiation potential.

Stem cells play an essential role in the development and repair of various tissues and organs in the body. They are currently being studied for their potential use in the treatment of a wide range of diseases and conditions, including cancer, diabetes, heart disease, and neurological disorders. However, more research is needed to fully understand the properties and capabilities of these cells before they can be used safely and effectively in clinical settings.

The Fluorescent Antibody Technique (FAT) is a type of immunofluorescence assay used in laboratory medicine and pathology for the detection and localization of specific antigens or antibodies in tissues, cells, or microorganisms. In this technique, a fluorescein-labeled antibody is used to selectively bind to the target antigen or antibody, forming an immune complex. When excited by light of a specific wavelength, the fluorescein label emits light at a longer wavelength, typically visualized as green fluorescence under a fluorescence microscope.

The FAT is widely used in diagnostic microbiology for the identification and characterization of various bacteria, viruses, fungi, and parasites. It has also been applied in the diagnosis of autoimmune diseases and certain cancers by detecting specific antibodies or antigens in patient samples. The main advantage of FAT is its high sensitivity and specificity, allowing for accurate detection and differentiation of various pathogens and disease markers. However, it requires specialized equipment and trained personnel to perform and interpret the results.

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

A "cell line, transformed" is a type of cell culture that has undergone a stable genetic alteration, which confers the ability to grow indefinitely in vitro, outside of the organism from which it was derived. These cells have typically been immortalized through exposure to chemical or viral carcinogens, or by introducing specific oncogenes that disrupt normal cell growth regulation pathways.

Transformed cell lines are widely used in scientific research because they offer a consistent and renewable source of biological material for experimentation. They can be used to study various aspects of cell biology, including signal transduction, gene expression, drug discovery, and toxicity testing. However, it is important to note that transformed cells may not always behave identically to their normal counterparts, and results obtained using these cells should be validated in more physiologically relevant systems when possible.

Transcriptional activation is the process by which a cell increases the rate of transcription of specific genes from DNA to RNA. This process is tightly regulated and plays a crucial role in various biological processes, including development, differentiation, and response to environmental stimuli.

Transcriptional activation occurs when transcription factors (proteins that bind to specific DNA sequences) interact with the promoter region of a gene and recruit co-activator proteins. These co-activators help to remodel the chromatin structure around the gene, making it more accessible for the transcription machinery to bind and initiate transcription.

Transcriptional activation can be regulated at multiple levels, including the availability and activity of transcription factors, the modification of histone proteins, and the recruitment of co-activators or co-repressors. Dysregulation of transcriptional activation has been implicated in various diseases, including cancer and genetic disorders.

Ubiquitin-protein ligases, also known as E3 ubiquitin ligases, are a group of enzymes that play a crucial role in the ubiquitination process. Ubiquitination is a post-translational modification where ubiquitin molecules are attached to specific target proteins, marking them for degradation by the proteasome or for other regulatory functions.

Ubiquitin-protein ligases catalyze the final step in this process by binding to both the ubiquitin protein and the target protein, facilitating the transfer of ubiquitin from an E2 ubiquitin-conjugating enzyme to the target protein. There are several different types of ubiquitin-protein ligases, each with their own specificity for particular target proteins and regulatory functions.

Ubiquitin-protein ligases have been implicated in various cellular processes such as protein degradation, DNA repair, signal transduction, and regulation of the cell cycle. Dysregulation of ubiquitination has been associated with several diseases, including cancer, neurodegenerative disorders, and inflammatory responses. Therefore, understanding the function and regulation of ubiquitin-protein ligases is an important area of research in biology and medicine.

Gene deletion is a type of mutation where a segment of DNA, containing one or more genes, is permanently lost or removed from a chromosome. This can occur due to various genetic mechanisms such as homologous recombination, non-homologous end joining, or other types of genomic rearrangements.

The deletion of a gene can have varying effects on the organism, depending on the function of the deleted gene and its importance for normal physiological processes. If the deleted gene is essential for survival, the deletion may result in embryonic lethality or developmental abnormalities. However, if the gene is non-essential or has redundant functions, the deletion may not have any noticeable effects on the organism's phenotype.

Gene deletions can also be used as a tool in genetic research to study the function of specific genes and their role in various biological processes. For example, researchers may use gene deletion techniques to create genetically modified animal models to investigate the impact of gene deletion on disease progression or development.

Gene knockdown techniques are methods used to reduce the expression or function of specific genes in order to study their role in biological processes. These techniques typically involve the use of small RNA molecules, such as siRNAs (small interfering RNAs) or shRNAs (short hairpin RNAs), which bind to and promote the degradation of complementary mRNA transcripts. This results in a decrease in the production of the protein encoded by the targeted gene.

Gene knockdown techniques are often used as an alternative to traditional gene knockout methods, which involve completely removing or disrupting the function of a gene. Knockdown techniques allow for more subtle and reversible manipulation of gene expression, making them useful for studying genes that are essential for cell survival or have redundant functions.

These techniques are widely used in molecular biology research to investigate gene function, genetic interactions, and disease mechanisms. However, it is important to note that gene knockdown can have off-target effects and may not completely eliminate the expression of the targeted gene, so results should be interpreted with caution.

Proto-oncogene proteins, such as c-MDM2, are normal cellular proteins that play crucial roles in regulating various cellular processes, including cell growth, differentiation, and apoptosis (programmed cell death). When these genes undergo mutations or are overexpressed, they can become oncogenes, which contribute to the development of cancer.

The c-MDM2 protein is a key regulator of the cell cycle and is involved in the negative regulation of the tumor suppressor protein p53. Under normal conditions, p53 helps prevent the formation of tumors by inducing cell cycle arrest or apoptosis in response to DNA damage or other stress signals. However, when c-MDM2 is overexpressed or mutated, it can bind and inhibit p53, leading to uncontrolled cell growth and increased risk of cancer development.

In summary, proto-oncogene proteins like c-MDM2 are important regulators of normal cellular processes, but when they become dysregulated through mutations or overexpression, they can contribute to the formation of tumors and cancer progression.

Fungal DNA refers to the genetic material present in fungi, which are a group of eukaryotic organisms that include microorganisms such as yeasts and molds, as well as larger organisms like mushrooms. The DNA of fungi, like that of all living organisms, is made up of nucleotides that are arranged in a double helix structure.

Fungal DNA contains the genetic information necessary for the growth, development, and reproduction of fungi. This includes the instructions for making proteins, which are essential for the structure and function of cells, as well as other important molecules such as enzymes and nucleic acids.

Studying fungal DNA can provide valuable insights into the biology and evolution of fungi, as well as their potential uses in medicine, agriculture, and industry. For example, researchers have used genetic engineering techniques to modify the DNA of fungi to produce drugs, biofuels, and other useful products. Additionally, understanding the genetic makeup of pathogenic fungi can help scientists develop new strategies for preventing and treating fungal infections.

E2F2 is a member of the E2F family of transcription factors, which are involved in the regulation of cell cycle progression and differentiation. Specifically, E2F2 forms a complex with a retinoblastoma protein (pRb) to regulate the expression of genes required for DNA replication and cell cycle progression. When pRb is phosphorylated and inactivated by cyclin-dependent kinases during the G1 phase of the cell cycle, E2F2 is released and can activate the transcription of its target genes, promoting the transition from G1 to S phase. In addition to its role in the cell cycle, E2F2 has also been implicated in the regulation of apoptosis and differentiation in certain contexts.

A nonmammalian embryo refers to the developing organism in animals other than mammals, from the fertilized egg (zygote) stage until hatching or birth. In nonmammalian species, the developmental stages and terminology differ from those used in mammals. The term "embryo" is generally applied to the developing organism up until a specific stage of development that is characterized by the formation of major organs and structures. After this point, the developing organism is referred to as a "larva," "juvenile," or other species-specific terminology.

The study of nonmammalian embryos has played an important role in our understanding of developmental biology and evolutionary developmental biology (evo-devo). By comparing the developmental processes across different animal groups, researchers can gain insights into the evolutionary origins and diversification of body plans and structures. Additionally, nonmammalian embryos are often used as model systems for studying basic biological processes, such as cell division, gene regulation, and pattern formation.

Tertiary protein structure refers to the three-dimensional arrangement of all the elements (polypeptide chains) of a single protein molecule. It is the highest level of structural organization and results from interactions between various side chains (R groups) of the amino acids that make up the protein. These interactions, which include hydrogen bonds, ionic bonds, van der Waals forces, and disulfide bridges, give the protein its unique shape and stability, which in turn determines its function. The tertiary structure of a protein can be stabilized by various factors such as temperature, pH, and the presence of certain ions. Any changes in these factors can lead to denaturation, where the protein loses its tertiary structure and thus its function.

An oocyte, also known as an egg cell or female gamete, is a large specialized cell found in the ovary of female organisms. It contains half the number of chromosomes as a normal diploid cell, as it is the product of meiotic division. Oocytes are surrounded by follicle cells and are responsible for the production of female offspring upon fertilization with sperm. The term "oocyte" specifically refers to the immature egg cell before it reaches full maturity and is ready for fertilization, at which point it is referred to as an ovum or egg.

A "knockout" mouse is a genetically engineered mouse in which one or more genes have been deleted or "knocked out" using molecular biology techniques. This allows researchers to study the function of specific genes and their role in various biological processes, as well as potential associations with human diseases. The mice are generated by introducing targeted DNA modifications into embryonic stem cells, which are then used to create a live animal. Knockout mice have been widely used in biomedical research to investigate gene function, disease mechanisms, and potential therapeutic targets.

A mammalian embryo is the developing offspring of a mammal, from the time of implantation of the fertilized egg (blastocyst) in the uterus until the end of the eighth week of gestation. During this period, the embryo undergoes rapid cell division and organ differentiation to form a complex structure with all the major organs and systems in place. This stage is followed by fetal development, which continues until birth. The study of mammalian embryos is important for understanding human development, evolution, and reproductive biology.

Cell size refers to the volume or spatial dimensions of a cell, which can vary widely depending on the type and function of the cell. In general, eukaryotic cells (cells with a true nucleus) tend to be larger than prokaryotic cells (cells without a true nucleus). The size of a cell is determined by various factors such as genetic makeup, the cell's role in the organism, and its environment.

The study of cell size and its relationship to cell function is an active area of research in biology, with implications for our understanding of cellular processes, evolution, and disease. For example, changes in cell size have been linked to various pathological conditions, including cancer and neurodegenerative disorders. Therefore, measuring and analyzing cell size can provide valuable insights into the health and function of cells and tissues.

Nucleic acid synthesis inhibitors are a class of antimicrobial, antiviral, or antitumor agents that block the synthesis of nucleic acids (DNA or RNA) by interfering with enzymes involved in their replication. These drugs can target various stages of nucleic acid synthesis, including DNA transcription, replication, and repair, as well as RNA transcription and processing.

Examples of nucleic acid synthesis inhibitors include:

1. Antibiotics like quinolones (e.g., ciprofloxacin), rifamycins (e.g., rifampin), and trimethoprim, which target bacterial DNA gyrase, RNA polymerase, or dihydrofolate reductase, respectively.
2. Antiviral drugs like reverse transcriptase inhibitors (e.g., zidovudine, lamivudine) and integrase strand transfer inhibitors (e.g., raltegravir), which target HIV replication by interfering with viral enzymes required for DNA synthesis.
3. Antitumor drugs like antimetabolites (e.g., methotrexate, 5-fluorouracil) and topoisomerase inhibitors (e.g., etoposide, doxorubicin), which interfere with DNA replication and repair in cancer cells.

These drugs have been widely used for treating various bacterial and viral infections, as well as cancers, due to their ability to selectively inhibit the growth of target cells without affecting normal cellular functions significantly. However, they may also cause side effects related to their mechanism of action or off-target effects on non-target cells.

'Drosophila proteins' refer to the proteins that are expressed in the fruit fly, Drosophila melanogaster. This organism is a widely used model system in genetics, developmental biology, and molecular biology research. The study of Drosophila proteins has contributed significantly to our understanding of various biological processes, including gene regulation, cell signaling, development, and aging.

Some examples of well-studied Drosophila proteins include:

1. HSP70 (Heat Shock Protein 70): A chaperone protein involved in protein folding and protection from stress conditions.
2. TUBULIN: A structural protein that forms microtubules, important for cell division and intracellular transport.
3. ACTIN: A cytoskeletal protein involved in muscle contraction, cell motility, and maintenance of cell shape.
4. BETA-GALACTOSIDASE (LACZ): A reporter protein often used to monitor gene expression patterns in transgenic flies.
5. ENDOGLIN: A protein involved in the development of blood vessels during embryogenesis.
6. P53: A tumor suppressor protein that plays a crucial role in preventing cancer by regulating cell growth and division.
7. JUN-KINASE (JNK): A signaling protein involved in stress response, apoptosis, and developmental processes.
8. DECAPENTAPLEGIC (DPP): A member of the TGF-β (Transforming Growth Factor Beta) superfamily, playing essential roles in embryonic development and tissue homeostasis.

These proteins are often studied using various techniques such as biochemistry, genetics, molecular biology, and structural biology to understand their functions, interactions, and regulation within the cell.

Oncogene proteins are derived from oncogenes, which are genes that have the potential to cause cancer. Normally, these genes help regulate cell growth and division, but when they become altered or mutated, they can become overactive and lead to uncontrolled cell growth and division, which is a hallmark of cancer. Oncogene proteins can contribute to tumor formation and progression by promoting processes such as cell proliferation, survival, angiogenesis, and metastasis. Examples of oncogene proteins include HER2/neu, EGFR, and BCR-ABL.

The Mitotic Index (MI) is a measure of cell proliferation that reflects the percentage of cells in a population or sample that are undergoing mitosis, which is the process of cell division. It is often expressed as the number of mitotic figures (dividing cells) per 100 or 1,000 cells counted in a microscopic field. The Mitotic Index is used in various fields, including pathology and research, to assess the growth fraction of cells in tissues or cultures, and to monitor the effects of treatments that affect cell division, such as chemotherapy or radiation therapy.

Chromosomal proteins, non-histone, are a diverse group of proteins that are associated with chromatin, the complex of DNA and histone proteins, but do not have the characteristic structure of histones. These proteins play important roles in various nuclear processes such as DNA replication, transcription, repair, recombination, and chromosome condensation and segregation during cell division. They can be broadly classified into several categories based on their functions, including architectural proteins, enzymes, transcription factors, and structural proteins. Examples of non-histone chromosomal proteins include high mobility group (HMG) proteins, poly(ADP-ribose) polymerases (PARPs), and condensins.

Geminin is a protein that plays a crucial role in the regulation of the cell cycle, specifically in the process of DNA replication. It functions as a regulatory protein that helps ensure the proper timing and completion of DNA replication before cell division occurs.

In more detail, Geminin binds to and inhibits the activity of several proteins involved in initiating DNA replication, such as CDT1 and CDC6. By doing so, it prevents the premature re-replication of DNA during the same cell cycle, which is essential for maintaining genomic stability.

Geminin is expressed in a cell cycle-dependent manner, with its levels peaking during the S and G2 phases, when DNA replication occurs, and declining during mitosis. This precise regulation of Geminin expression and activity helps coordinate the various stages of the cell cycle and ensures that DNA replication and cell division occur in a controlled and orderly fashion.

It's worth noting that deregulation of Geminin expression or function has been implicated in several human diseases, including cancer, where abnormal cell cycle control can contribute to uncontrolled cell growth and proliferation.

Gene silencing is a process by which the expression of a gene is blocked or inhibited, preventing the production of its corresponding protein. This can occur naturally through various mechanisms such as RNA interference (RNAi), where small RNAs bind to and degrade specific mRNAs, or DNA methylation, where methyl groups are added to the DNA molecule, preventing transcription. Gene silencing can also be induced artificially using techniques such as RNAi-based therapies, antisense oligonucleotides, or CRISPR-Cas9 systems, which allow for targeted suppression of gene expression in research and therapeutic applications.

The Ki-67 antigen is a cellular protein that is expressed in all active phases of the cell cycle (G1, S, G2, and M), but not in the resting phase (G0). It is often used as a marker for cell proliferation and can be found in high concentrations in rapidly dividing cells. Immunohistochemical staining for Ki-67 can help to determine the growth fraction of a group of cells, which can be useful in the diagnosis and prognosis of various malignancies, including cancer. The level of Ki-67 expression is often associated with the aggressiveness of the tumor and its response to treatment.

Cell growth processes refer to the series of events that occur within a cell leading to an increase in its size, mass, and number of organelles. These processes are essential for the development, maintenance, and reproduction of all living organisms. The main cell growth processes include:

1. Cell Cycle: It is the sequence of events that a eukaryotic cell goes through from one cell division (mitosis) to the next. The cell cycle consists of four distinct phases: G1 phase (growth and preparation for DNA replication), S phase (DNA synthesis), G2 phase (preparation for mitosis), and M phase (mitosis or meiosis).

2. DNA Replication: It is the process by which a cell makes an identical copy of its DNA molecule before cell division. This ensures that each daughter cell receives an exact replica of the parent cell's genetic material.

3. Protein Synthesis: Cells grow by increasing their protein content, which is achieved through the process of protein synthesis. This involves transcribing DNA into mRNA (transcription) and then translating that mRNA into a specific protein sequence (translation).

4. Cellular Metabolism: It refers to the sum total of all chemical reactions that occur within a cell to maintain life. These reactions include catabolic processes, which break down nutrients to release energy, and anabolic processes, which use energy to build complex molecules like proteins, lipids, and carbohydrates.

5. Cell Signaling: Cells communicate with each other through intricate signaling pathways that help coordinate growth, differentiation, and survival. These signals can come from within the cell (intracellular) or from outside the cell (extracellular).

6. Cell Division: Also known as mitosis, it is the process by which a single cell divides into two identical daughter cells. This ensures that each new cell contains an exact copy of the parent cell's genetic material and allows for growth and repair of tissues.

7. Apoptosis: It is a programmed cell death process that helps maintain tissue homeostasis by eliminating damaged or unnecessary cells. Dysregulation of apoptosis can lead to diseases such as cancer and autoimmune disorders.

Metaphase is a phase in the cell division process (mitosis or meiosis) where the chromosomes align in the middle of the cell, also known as the metaphase plate or equatorial plane. During this stage, each chromosome consists of two sister chromatids attached to each other by a protein complex called the centromere. The spindle fibers from opposite poles of the cell attach to the centromeres of each chromosome, and through a process called congression, they align the chromosomes in the middle of the cell. This alignment allows for accurate segregation of genetic material during the subsequent anaphase stage.

Phosphoproteins are proteins that have been post-translationally modified by the addition of a phosphate group (-PO3H2) onto specific amino acid residues, most commonly serine, threonine, or tyrosine. This process is known as phosphorylation and is mediated by enzymes called kinases. Phosphoproteins play crucial roles in various cellular processes such as signal transduction, cell cycle regulation, metabolism, and gene expression. The addition or removal of a phosphate group can activate or inhibit the function of a protein, thereby serving as a switch to control its activity. Phosphoproteins can be detected and quantified using techniques such as Western blotting, mass spectrometry, and immunofluorescence.

Epithelial cells are types of cells that cover the outer surfaces of the body, line the inner surfaces of organs and glands, and form the lining of blood vessels and body cavities. They provide a protective barrier against the external environment, regulate the movement of materials between the internal and external environments, and are involved in the sense of touch, temperature, and pain. Epithelial cells can be squamous (flat and thin), cuboidal (square-shaped and of equal height), or columnar (tall and narrow) in shape and are classified based on their location and function.

"Nude mice" is a term used in the field of laboratory research to describe a strain of mice that have been genetically engineered to lack a functional immune system. Specifically, nude mice lack a thymus gland and have a mutation in the FOXN1 gene, which results in a failure to develop a mature T-cell population. This means that they are unable to mount an effective immune response against foreign substances or organisms.

The name "nude" refers to the fact that these mice also have a lack of functional hair follicles, resulting in a hairless or partially hairless phenotype. This feature is actually a secondary consequence of the same genetic mutation that causes their immune deficiency.

Nude mice are commonly used in research because their weakened immune system makes them an ideal host for transplanted tumors, tissues, and cells from other species, including humans. This allows researchers to study the behavior of these foreign substances in a living organism without the complication of an immune response. However, it's important to note that because nude mice lack a functional immune system, they must be kept in sterile conditions and are more susceptible to infection than normal mice.

Cyclin A1 is a type of cyclin protein that regulates the cell cycle, particularly during the S and G2 phases. It forms a complex with and acts as a regulatory subunit of cyclin-dependent kinase 2 (CDK2), helping to control the transition from the G1 phase to the S phase and from the S phase to the G2 phase. Cyclin A1 is expressed in various tissues, including ovary, testis, bone marrow, and lymphoid cells. Overexpression or dysregulation of cyclin A1 has been implicated in several types of cancer, making it a potential target for cancer therapy.

Temperature, in a medical context, is a measure of the degree of hotness or coldness of a body or environment. It is usually measured using a thermometer and reported in degrees Celsius (°C), degrees Fahrenheit (°F), or kelvin (K). In the human body, normal core temperature ranges from about 36.5-37.5°C (97.7-99.5°F) when measured rectally, and can vary slightly depending on factors such as time of day, physical activity, and menstrual cycle. Elevated body temperature is a common sign of infection or inflammation, while abnormally low body temperature can indicate hypothermia or other medical conditions.

The term "DNA, neoplasm" is not a standard medical term or concept. DNA refers to deoxyribonucleic acid, which is the genetic material present in the cells of living organisms. A neoplasm, on the other hand, is a tumor or growth of abnormal tissue that can be benign (non-cancerous) or malignant (cancerous).

In some contexts, "DNA, neoplasm" may refer to genetic alterations found in cancer cells. These genetic changes can include mutations, amplifications, deletions, or rearrangements of DNA sequences that contribute to the development and progression of cancer. Identifying these genetic abnormalities can help doctors diagnose and treat certain types of cancer more effectively.

However, it's important to note that "DNA, neoplasm" is not a term that would typically be used in medical reports or research papers without further clarification. If you have any specific questions about DNA changes in cancer cells or neoplasms, I would recommend consulting with a healthcare professional or conducting further research on the topic.

C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.

The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.

C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.

One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.

Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.

Vpr is a protein that is encoded by the viral protein R (vpr) gene in the human immunodeficiency virus (HIV). The vpr gene is one of the accessory genes in HIV that are not essential for viral replication but contribute to the pathogenesis of the infection.

The Vpr protein plays a role in the regulation of the viral life cycle and the host cell response to infection. It can induce cell cycle arrest, promote nuclear import of the viral DNA, and enhance viral transcription. Additionally, Vpr has been shown to have pro-apoptotic activity, contributing to CD4+ T cell depletion and disease progression in HIV infection.

Vpr is also involved in the transport of the viral particle into the nucleus of non-dividing cells, such as macrophages, allowing for efficient replication in these cells. Overall, Vpr is an important virulence factor in HIV infection and has been a target for antiretroviral therapy development.

Cyclin G1 is a type of protein that belongs to the cyclin family, which are involved in the regulation of the cell cycle. The cell cycle is the series of events that take place as a cell grows, copies its DNA, and divides into two daughter cells.

Cyclin G1 regulates the cell cycle by interacting with various cyclin-dependent kinases (CDKs), which are enzymes that help control the progression of the cell cycle. Specifically, Cyclin G1 has been shown to inhibit the activity of CDK1 and CDK2, which play important roles in regulating the transition from the G1 phase to the S phase of the cell cycle.

Cyclin G1 has also been implicated in other cellular processes, including DNA damage repair, apoptosis (programmed cell death), and tumor suppression. Dysregulation of Cyclin G1 has been linked to various types of cancer, making it a potential target for cancer therapy.

HL-60 cells are a type of human promyelocytic leukemia cell line that is commonly used in scientific research. They are named after the hospital where they were first isolated, the Hospital of the University of Pennsylvania (HUP) and the 60th culture attempt to grow these cells.

HL-60 cells have the ability to differentiate into various types of blood cells, such as granulocytes, monocytes, and macrophages, when exposed to certain chemical compounds or under specific culturing conditions. This makes them a valuable tool for studying the mechanisms of cell differentiation, proliferation, and apoptosis (programmed cell death).

HL-60 cells are also often used in toxicity studies, drug discovery and development, and research on cancer, inflammation, and infectious diseases. They can be easily grown in the lab and have a stable genotype, making them ideal for use in standardized experiments and comparisons between different studies.

Pregnancy is a physiological state or condition where a fertilized egg (zygote) successfully implants and grows in the uterus of a woman, leading to the development of an embryo and finally a fetus. This process typically spans approximately 40 weeks, divided into three trimesters, and culminates in childbirth. Throughout this period, numerous hormonal and physical changes occur to support the growing offspring, including uterine enlargement, breast development, and various maternal adaptations to ensure the fetus's optimal growth and well-being.

Saccharomycetales is an order of fungi that are commonly known as "true yeasts." They are characterized by their single-celled growth and ability to reproduce through budding or fission. These organisms are widely distributed in nature and can be found in a variety of environments, including soil, water, and on the surfaces of plants and animals.

Many species of Saccharomycetales are used in industrial processes, such as the production of bread, beer, and wine. They are also used in biotechnology to produce various enzymes, vaccines, and other products. Some species of Saccharomycetales can cause diseases in humans and animals, particularly in individuals with weakened immune systems. These infections, known as candidiasis or thrush, can affect various parts of the body, including the skin, mouth, and genital area.

E2F4 is a member of the E2F family of transcription factors, which are involved in the regulation of cell cycle progression and differentiation. E2F4 can function as both a transcriptional activator and repressor, depending on which proteins it interacts with. It primarily acts as a repressor, binding to DNA and preventing the transcription of target genes involved in cell cycle progression. E2F4 has been shown to play important roles in various biological processes, including development, differentiation, and tumor suppression.

Estrus is a term used in veterinary medicine to describe the physiological and behavioral state of female mammals that are ready to mate and conceive. It refers to the period of time when the female's reproductive system is most receptive to fertilization.

During estrus, the female's ovaries release one or more mature eggs (ovulation) into the fallopian tubes, where they can be fertilized by sperm from a male. This phase of the estrous cycle is often accompanied by changes in behavior and physical appearance, such as increased vocalization, restlessness, and swelling of the genital area.

The duration and frequency of estrus vary widely among different species of mammals. In some animals, such as dogs and cats, estrus occurs regularly at intervals of several weeks or months, while in others, such as cows and mares, it may only occur once or twice a year.

It's important to note that the term "estrus" is not used to describe human reproductive physiology. In humans, the equivalent phase of the menstrual cycle is called ovulation.

Centrioles are small, cylindrical structures found in the centrosome of animal cells. They play a crucial role in organizing the microtubules that make up the cell's cytoskeleton and are also involved in the formation of the spindle apparatus during cell division. A typical centriole is made up of nine sets of triplet microtubules arranged in a ring-like fashion around a central hub or core.

Centrioles have two main functions:

1. Microtubule Organization: Centrioles serve as the primary site for microtubule nucleation and organization within the cell. They help to form the mitotic spindle during cell division, which is responsible for separating replicated chromosomes into two identical sets that are distributed equally between the two daughter cells.

2. Formation of Cilia and Flagella: In specialized cells, centrioles can also function as basal bodies for the formation of cilia and flagella. These hair-like structures protrude from the cell surface and play a role in cell movement and the movement of extracellular fluids over the cell surface.

It is important to note that plants and fungi do not have centrioles, and their cells use alternative mechanisms for microtubule organization and cell division.

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

"Xenopus proteins" refer to the proteins that are expressed or isolated from the Xenopus species, which are primarily used as model organisms in biological and biomedical research. The most commonly used Xenopus species for research are the African clawed frogs, Xenopus laevis and Xenopus tropicalis. These proteins play crucial roles in various cellular processes and functions, and they serve as valuable tools to study different aspects of molecular biology, developmental biology, genetics, and biochemistry.

Some examples of Xenopus proteins that are widely studied include:

1. Xenopus Histones: These are the proteins that package DNA into nucleosomes, which are the fundamental units of chromatin in eukaryotic cells. They play a significant role in gene regulation and epigenetic modifications.
2. Xenopus Cyclins and Cyclin-dependent kinases (CDKs): These proteins regulate the cell cycle and control cell division, differentiation, and apoptosis.
3. Xenopus Transcription factors: These proteins bind to specific DNA sequences and regulate gene expression during development and in response to various stimuli.
4. Xenopus Signaling molecules: These proteins are involved in intracellular signaling pathways that control various cellular processes, such as cell growth, differentiation, migration, and survival.
5. Xenopus Cytoskeletal proteins: These proteins provide structural support to the cells and regulate their shape, motility, and organization.
6. Xenopus Enzymes: These proteins catalyze various biochemical reactions in the cell, such as metabolic pathways, DNA replication, transcription, and translation.

Overall, Xenopus proteins are essential tools for understanding fundamental biological processes and have contributed significantly to our current knowledge of molecular biology, genetics, and developmental biology.

F-box proteins are a family of proteins that are characterized by the presence of an F-box domain, which is a motif of about 40-50 amino acids. This domain is responsible for binding to Skp1, a component of the SCF (Skp1-Cul1-F-box protein) E3 ubiquitin ligase complex. The F-box proteins serve as the substrate recognition subunit of this complex and are involved in targeting specific proteins for ubiquitination and subsequent degradation by the 26S proteasome.

There are multiple types of F-box proteins, including FBXW (also known as β-TrCP), FBXL, and FBLX, each with different substrate specificities. These proteins play important roles in various cellular processes such as cell cycle regulation, signal transduction, and DNA damage response by controlling the stability of key regulatory proteins.

Abnormal regulation of F-box proteins has been implicated in several human diseases, including cancer, developmental disorders, and neurodegenerative diseases.

Progesterone is a steroid hormone that is primarily produced in the ovaries during the menstrual cycle and in pregnancy. It plays an essential role in preparing the uterus for implantation of a fertilized egg and maintaining the early stages of pregnancy. Progesterone works to thicken the lining of the uterus, creating a nurturing environment for the developing embryo.

During the menstrual cycle, progesterone is produced by the corpus luteum, a temporary structure formed in the ovary after an egg has been released from a follicle during ovulation. If pregnancy does not occur, the levels of progesterone will decrease, leading to the shedding of the uterine lining and menstruation.

In addition to its reproductive functions, progesterone also has various other effects on the body, such as helping to regulate the immune system, supporting bone health, and potentially influencing mood and cognition. Progesterone can be administered medically in the form of oral pills, intramuscular injections, or vaginal suppositories for various purposes, including hormone replacement therapy, contraception, and managing certain gynecological conditions.

Chromosomes are thread-like structures that exist in the nucleus of cells, carrying genetic information in the form of genes. They are composed of DNA and proteins, and are typically present in pairs in the nucleus, with one set inherited from each parent. In humans, there are 23 pairs of chromosomes for a total of 46 chromosomes. Chromosomes come in different shapes and forms, including sex chromosomes (X and Y) that determine the biological sex of an individual. Changes or abnormalities in the number or structure of chromosomes can lead to genetic disorders and diseases.

Cytokinesis is the part of the cell division process (mitosis or meiosis) in which the cytoplasm of a single eukaryotic cell divides into two daughter cells. It usually begins after telophase, and it involves the constriction of a contractile ring composed of actin filaments and myosin motor proteins that forms at the equatorial plane of the cell. This results in the formation of a cleavage furrow, which deepens and eventually leads to the physical separation of the two daughter cells. Cytokinesis is essential for cell reproduction and growth in multicellular organisms, and its failure can lead to various developmental abnormalities or diseases.

Radiation tolerance, in the context of medicine and particularly radiation oncology, refers to the ability of tissues or organs to withstand and recover from exposure to ionizing radiation without experiencing significant damage or loss of function. It is often used to describe the maximum dose of radiation that can be safely delivered to a specific area of the body during radiotherapy treatments.

Radiation tolerance varies depending on the type and location of the tissue or organ. For example, some tissues such as the brain, spinal cord, and lungs have lower radiation tolerance than others like the skin or bone. Factors that can affect radiation tolerance include the total dose of radiation, the fractionation schedule (the number and size of radiation doses), the volume of tissue treated, and the individual patient's overall health and genetic factors.

Assessing radiation tolerance is critical in designing safe and effective radiotherapy plans for cancer patients, as excessive radiation exposure can lead to serious side effects such as radiation-induced injury, fibrosis, or even secondary malignancies.

Ionizing radiation is a type of radiation that carries enough energy to ionize atoms or molecules, which means it can knock electrons out of their orbits and create ions. These charged particles can cause damage to living tissue and DNA, making ionizing radiation dangerous to human health. Examples of ionizing radiation include X-rays, gamma rays, and some forms of subatomic particles such as alpha and beta particles. The amount and duration of exposure to ionizing radiation are important factors in determining the potential health effects, which can range from mild skin irritation to an increased risk of cancer and other diseases.

Immunoprecipitation (IP) is a research technique used in molecular biology and immunology to isolate specific antigens or antibodies from a mixture. It involves the use of an antibody that recognizes and binds to a specific antigen, which is then precipitated out of solution using various methods, such as centrifugation or chemical cross-linking.

In this technique, an antibody is first incubated with a sample containing the antigen of interest. The antibody specifically binds to the antigen, forming an immune complex. This complex can then be captured by adding protein A or G agarose beads, which bind to the constant region of the antibody. The beads are then washed to remove any unbound proteins, leaving behind the precipitated antigen-antibody complex.

Immunoprecipitation is a powerful tool for studying protein-protein interactions, post-translational modifications, and signal transduction pathways. It can also be used to detect and quantify specific proteins in biological samples, such as cells or tissues, and to identify potential biomarkers of disease.

Caspase-3 is a type of protease enzyme that plays a central role in the execution-phase of cell apoptosis, or programmed cell death. It's also known as CPP32 (CPP for ced-3 protease precursor) or apopain. Caspase-3 is produced as an inactive protein that is activated when cleaved by other caspases during the early stages of apoptosis. Once activated, it cleaves a variety of cellular proteins, including structural proteins, enzymes, and signal transduction proteins, leading to the characteristic morphological and biochemical changes associated with apoptotic cell death. Caspase-3 is often referred to as the "death protease" because of its crucial role in executing the cell death program.

Post-translational protein processing refers to the modifications and changes that proteins undergo after their synthesis on ribosomes, which are complex molecular machines responsible for protein synthesis. These modifications occur through various biochemical processes and play a crucial role in determining the final structure, function, and stability of the protein.

The process begins with the translation of messenger RNA (mRNA) into a linear polypeptide chain, which is then subjected to several post-translational modifications. These modifications can include:

1. Proteolytic cleavage: The removal of specific segments or domains from the polypeptide chain by proteases, resulting in the formation of mature, functional protein subunits.
2. Chemical modifications: Addition or modification of chemical groups to the side chains of amino acids, such as phosphorylation (addition of a phosphate group), glycosylation (addition of sugar moieties), methylation (addition of a methyl group), acetylation (addition of an acetyl group), and ubiquitination (addition of a ubiquitin protein).
3. Disulfide bond formation: The oxidation of specific cysteine residues within the polypeptide chain, leading to the formation of disulfide bonds between them. This process helps stabilize the three-dimensional structure of proteins, particularly in extracellular environments.
4. Folding and assembly: The acquisition of a specific three-dimensional conformation by the polypeptide chain, which is essential for its function. Chaperone proteins assist in this process to ensure proper folding and prevent aggregation.
5. Protein targeting: The directed transport of proteins to their appropriate cellular locations, such as the nucleus, mitochondria, endoplasmic reticulum, or plasma membrane. This is often facilitated by specific signal sequences within the protein that are recognized and bound by transport machinery.

Collectively, these post-translational modifications contribute to the functional diversity of proteins in living organisms, allowing them to perform a wide range of cellular processes, including signaling, catalysis, regulation, and structural support.

Phosphoprotein phosphatases (PPPs) are a family of enzymes that play a crucial role in the regulation of various cellular processes by removing phosphate groups from serine, threonine, and tyrosine residues on proteins. Phosphorylation is a post-translational modification that regulates protein function, localization, and stability, and dephosphorylation by PPPs is essential for maintaining the balance of this regulation.

The PPP family includes several subfamilies, such as PP1, PP2A, PP2B (also known as calcineurin), PP4, PP5, and PP6. Each subfamily has distinct substrate specificities and regulatory mechanisms. For example, PP1 and PP2A are involved in the regulation of metabolism, signal transduction, and cell cycle progression, while PP2B is involved in immune response and calcium signaling.

Dysregulation of PPPs has been implicated in various diseases, including cancer, neurodegenerative disorders, and cardiovascular disease. Therefore, understanding the function and regulation of PPPs is important for developing therapeutic strategies to target these diseases.

Green Fluorescent Protein (GFP) is not a medical term per se, but a scientific term used in the field of molecular biology. GFP is a protein that exhibits bright green fluorescence when exposed to light, particularly blue or ultraviolet light. It was originally discovered in the jellyfish Aequorea victoria.

In medical and biological research, scientists often use recombinant DNA technology to introduce the gene for GFP into other organisms, including bacteria, plants, and animals, including humans. This allows them to track the expression and localization of specific genes or proteins of interest in living cells, tissues, or even whole organisms.

The ability to visualize specific cellular structures or processes in real-time has proven invaluable for a wide range of research areas, from studying the development and function of organs and organ systems to understanding the mechanisms of diseases and the effects of therapeutic interventions.

NIH 3T3 cells are a type of mouse fibroblast cell line that was developed by the National Institutes of Health (NIH). The "3T3" designation refers to the fact that these cells were derived from embryonic Swiss mouse tissue and were able to be passaged (i.e., subcultured) more than three times in tissue culture.

NIH 3T3 cells are widely used in scientific research, particularly in studies involving cell growth and differentiation, signal transduction, and gene expression. They have also been used as a model system for studying the effects of various chemicals and drugs on cell behavior. NIH 3T3 cells are known to be relatively easy to culture and maintain, and they have a stable, flat morphology that makes them well-suited for use in microscopy studies.

It is important to note that, as with any cell line, it is essential to verify the identity and authenticity of NIH 3T3 cells before using them in research, as contamination or misidentification can lead to erroneous results.

Polyploidy is a condition in which a cell or an organism has more than two sets of chromosomes, unlike the typical diploid state where there are only two sets (one from each parent). Polyploidy can occur through various mechanisms such as errors during cell division, fusion of egg and sperm cells that have an abnormal number of chromosomes, or through the reproduction process in plants.

Polyploidy is common in the plant kingdom, where it often leads to larger size, increased biomass, and sometimes hybrid vigor. However, in animals, polyploidy is less common and usually occurs in only certain types of cells or tissues, as most animals require a specific number of chromosomes for normal development and reproduction. In humans, polyploidy is typically not compatible with life and can lead to developmental abnormalities and miscarriage.

Protein-kinase B, also known as AKT, is a group of intracellular proteins that play a crucial role in various cellular processes such as glucose metabolism, apoptosis, cell proliferation, transcription, and cell migration. The AKT family includes three isoforms: AKT1, AKT2, and AKT3, which are encoded by the genes PKBalpha, PKBbeta, and PKBgamma, respectively.

Proto-oncogene proteins c-AKT refer to the normal, non-mutated forms of these proteins that are involved in the regulation of cell growth and survival under physiological conditions. However, when these genes are mutated or overexpressed, they can become oncogenes, leading to uncontrolled cell growth and cancer development.

Activation of c-AKT occurs through a signaling cascade that begins with the binding of extracellular ligands such as insulin-like growth factor 1 (IGF-1) or epidermal growth factor (EGF) to their respective receptors on the cell surface. This triggers a series of phosphorylation events that ultimately lead to the activation of c-AKT, which then phosphorylates downstream targets involved in various cellular processes.

In summary, proto-oncogene proteins c-AKT are normal intracellular proteins that play essential roles in regulating cell growth and survival under physiological conditions. However, their dysregulation can contribute to cancer development and progression.

Cyclin-dependent kinases (CDKs) are a family of serine/threonine protein kinases that play crucial roles in regulating the cell cycle, transcription, and other cellular processes. They are activated by binding to cyclin proteins, which accumulate and degrade at specific stages of the cell cycle. The activation of CDKs leads to phosphorylation of various downstream target proteins, resulting in the promotion or inhibition of different cell cycle events. Dysregulation of CDKs has been implicated in several human diseases, including cancer, and they are considered important targets for drug development.

Protein transport, in the context of cellular biology, refers to the process by which proteins are actively moved from one location to another within or between cells. This is a crucial mechanism for maintaining proper cell function and regulation.

Intracellular protein transport involves the movement of proteins within a single cell. Proteins can be transported across membranes (such as the nuclear envelope, endoplasmic reticulum, Golgi apparatus, or plasma membrane) via specialized transport systems like vesicles and transport channels.

Intercellular protein transport refers to the movement of proteins from one cell to another, often facilitated by exocytosis (release of proteins in vesicles) and endocytosis (uptake of extracellular substances via membrane-bound vesicles). This is essential for communication between cells, immune response, and other physiological processes.

It's important to note that any disruption in protein transport can lead to various diseases, including neurological disorders, cancer, and metabolic conditions.

E2F3 is a member of the E2F family of transcription factors, which are involved in the regulation of cell cycle progression and apoptosis (programmed cell death). Specifically, E2F3 can function as either an activator or a repressor of transcription, depending on whether it forms a complex with a retinoblastoma protein (pRb) or not.

When E2F3 is bound to pRb, it acts as a transcriptional repressor and helps to keep cells in a quiescent state by preventing the expression of genes required for DNA replication and cell cycle progression. However, when pRb is phosphorylated and inactivated by cyclin-dependent kinases during the G1 phase of the cell cycle, E2F3 is released and can then function as a transcriptional activator.

Activation of E2F3 leads to the expression of genes required for DNA replication and entry into the S phase of the cell cycle. In addition to its role in regulating the cell cycle, E2F3 has also been implicated in the development and progression of various types of cancer, including breast, lung, and prostate cancer. Dysregulation of E2F3 activity can contribute to uncontrolled cell growth and tumor formation.

A plasmid is a small, circular, double-stranded DNA molecule that is separate from the chromosomal DNA of a bacterium or other organism. Plasmids are typically not essential for the survival of the organism, but they can confer beneficial traits such as antibiotic resistance or the ability to degrade certain types of pollutants.

Plasmids are capable of replicating independently of the chromosomal DNA and can be transferred between bacteria through a process called conjugation. They often contain genes that provide resistance to antibiotics, heavy metals, and other environmental stressors. Plasmids have also been engineered for use in molecular biology as cloning vectors, allowing scientists to replicate and manipulate specific DNA sequences.

Plasmids are important tools in genetic engineering and biotechnology because they can be easily manipulated and transferred between organisms. They have been used to produce vaccines, diagnostic tests, and genetically modified organisms (GMOs) for various applications, including agriculture, medicine, and industry.

Tumor suppressor genes are a type of gene that helps to regulate and prevent cells from growing and dividing too rapidly or in an uncontrolled manner. They play a critical role in preventing the formation of tumors and cancer. When functioning properly, tumor suppressor genes help to repair damaged DNA, control the cell cycle, and trigger programmed cell death (apoptosis) when necessary. However, when these genes are mutated or altered, they can lose their ability to function correctly, leading to uncontrolled cell growth and the development of tumors. Examples of tumor suppressor genes include TP53, BRCA1, and BRCA2.

Complementary DNA (cDNA) is a type of DNA that is synthesized from a single-stranded RNA molecule through the process of reverse transcription. In this process, the enzyme reverse transcriptase uses an RNA molecule as a template to synthesize a complementary DNA strand. The resulting cDNA is therefore complementary to the original RNA molecule and is a copy of its coding sequence, but it does not contain non-coding regions such as introns that are present in genomic DNA.

Complementary DNA is often used in molecular biology research to study gene expression, protein function, and other genetic phenomena. For example, cDNA can be used to create cDNA libraries, which are collections of cloned cDNA fragments that represent the expressed genes in a particular cell type or tissue. These libraries can then be screened for specific genes or gene products of interest. Additionally, cDNA can be used to produce recombinant proteins in heterologous expression systems, allowing researchers to study the structure and function of proteins that may be difficult to express or purify from their native sources.

14-3-3 proteins are a family of conserved regulatory molecules found in eukaryotic cells. They are involved in various cellular processes, such as signal transduction, cell cycle regulation, and apoptosis (programmed cell death). These proteins bind to specific phosphoserine-containing motifs on their target proteins, thereby modulating their activity, localization, or stability. Dysregulation of 14-3-3 proteins has been implicated in several human diseases, including cancer, neurodegenerative disorders, and diabetes.

Aurora kinases are a family of serine/threonine protein kinases that play crucial roles in the regulation of cell division. There are three members of the Aurora kinase family, designated as Aurora A, Aurora B, and Aurora C. These kinases are involved in the proper separation of chromosomes during mitosis and meiosis, and their dysregulation has been implicated in various types of cancer.

Aurora A is primarily located at the centrosomes and spindle poles during cell division, where it regulates centrosome maturation, bipolar spindle formation, and chromosome segregation. Aurora B, on the other hand, is a component of the chromosomal passenger complex (CPC) that localizes to the centromeres during prophase and moves to the spindle midzone during anaphase. It plays essential roles in kinetochore-microtubule attachment, chromosome alignment, and cytokinesis. Aurora C is most similar to Aurora B and appears to have overlapping functions with it, although its specific roles are less well understood.

Dysregulation of Aurora kinases has been associated with various types of cancer, including breast, ovarian, colon, and lung cancers. Overexpression or amplification of Aurora A is observed in many cancers, leading to chromosomal instability and aneuploidy. Inhibition of Aurora kinases has emerged as a potential therapeutic strategy for cancer treatment, with several small molecule inhibitors currently under investigation in clinical trials.

Transgenic mice are genetically modified rodents that have incorporated foreign DNA (exogenous DNA) into their own genome. This is typically done through the use of recombinant DNA technology, where a specific gene or genetic sequence of interest is isolated and then introduced into the mouse embryo. The resulting transgenic mice can then express the protein encoded by the foreign gene, allowing researchers to study its function in a living organism.

The process of creating transgenic mice usually involves microinjecting the exogenous DNA into the pronucleus of a fertilized egg, which is then implanted into a surrogate mother. The offspring that result from this procedure are screened for the presence of the foreign DNA, and those that carry the desired genetic modification are used to establish a transgenic mouse line.

Transgenic mice have been widely used in biomedical research to model human diseases, study gene function, and test new therapies. They provide a valuable tool for understanding complex biological processes and developing new treatments for a variety of medical conditions.

The "vpr gene products" refer to the proteins produced by the vpr gene in the human immunodeficiency virus (HIV). The vpr gene is one of the accessory genes found in the HIV genome. It encodes for a viral protein, Vpr, which plays several roles during the viral replication cycle and infection process.

Vpr is a small, 96-amino acid protein that has multiple functions:

1. Nuclear localization: Vpr helps in the transport of the viral DNA into the nucleus of the infected cell by interacting with importin-α, a cellular protein responsible for nuclear import.
2. Cell cycle arrest: Vpr can induce G2 phase cell cycle arrest in infected cells, which may promote efficient viral replication and assembly.
3. Apoptosis (programmed cell death): Vpr has been shown to induce apoptosis in certain cell types, contributing to the cytopathic effects of HIV infection.
4. Virion packaging: Vpr is incorporated into newly assembled virions during the budding process, allowing it to be transmitted to neighboring cells during subsequent rounds of infection.
5. Transcriptional regulation: Vpr can interact with cellular proteins involved in transcriptional regulation, potentially modulating host gene expression and contributing to HIV pathogenesis.

Overall, vpr gene products play a significant role in the HIV replication cycle and contribute to viral pathogenesis by inducing cell cycle arrest, apoptosis, and altering host cell gene expression.

Ploidy is a term used in genetics to describe the number of sets of chromosomes in a cell or an organism. The ploidy level can have important implications for genetic inheritance and expression, as well as for evolutionary processes such as speciation and hybridization.

In most animals, including humans, the normal ploidy level is diploid, meaning that each cell contains two sets of chromosomes - one set inherited from each parent. However, there are also many examples of polyploidy, in which an organism has more than two sets of chromosomes.

Polyploidy can arise through various mechanisms, such as genome duplication or hybridization between different species. In some cases, polyploidy may confer evolutionary advantages, such as increased genetic diversity and adaptability to new environments. However, it can also lead to reproductive isolation and the formation of new species.

In plants, polyploidy is relatively common and has played a significant role in their evolution and diversification. Many crop plants are polyploids, including wheat, cotton, and tobacco. In some cases, artificial induction of polyploidy has been used to create new varieties with desirable traits for agriculture and horticulture.

Overall, ploidy is an important concept in genetics and evolution, with implications for a wide range of biological processes and phenomena.

In genetics, sequence alignment is the process of arranging two or more DNA, RNA, or protein sequences to identify regions of similarity or homology between them. This is often done using computational methods to compare the nucleotide or amino acid sequences and identify matching patterns, which can provide insight into evolutionary relationships, functional domains, or potential genetic disorders. The alignment process typically involves adjusting gaps and mismatches in the sequences to maximize the similarity between them, resulting in an aligned sequence that can be visually represented and analyzed.

"Serum-free culture media" refers to a type of nutrient medium used in cell culture and tissue engineering that does not contain fetal bovine serum (FBS) or other animal serums. Instead, it is supplemented with defined, chemically-defined components such as hormones, growth factors, vitamins, and amino acids.

The use of serum-free media offers several advantages over traditional media formulations that contain serum. For example, it reduces the risk of contamination with adventitious agents, such as viruses and prions, that may be present in animal serums. Additionally, it allows for greater control over the culture environment, as the concentration and composition of individual components can be carefully regulated. This is particularly important in applications where precise control over cell behavior is required, such as in the production of therapeutic proteins or in stem cell research.

However, serum-free media may not be suitable for all cell types, as some cells require the complex mixture of growth factors and other components found in animal serums to survive and proliferate. Therefore, it is important to carefully evaluate the needs of each specific cell type when selecting a culture medium.

Cyclin-Dependent Kinase Inhibitor p18, also known as CDKN2C or INK4c, is a protein that regulates the cell cycle. It inhibits the activity of cyclin-dependent kinases (CDKs), specifically the CDK4 and CDK6 proteins, which play crucial roles in regulating the progression of the cell cycle.

The p18 protein functions as a tumor suppressor by preventing the phosphorylation and activation of the retinoblastoma protein (pRb) by CDK4/6. When pRb is not phosphorylated, it remains bound to E2F transcription factors, inhibiting their ability to promote the expression of genes required for cell cycle progression.

Mutations or deletions in the CDKN2C gene can lead to uncontrolled cell growth and contribute to tumor development, making p18 an important factor in cancer biology and potential therapeutic target.

Retinoblastoma genes, often referred to as RB1, are tumor suppressor genes that play a critical role in regulating cell growth and division. When functioning properly, these genes help prevent the development of cancer by ensuring that cells divide and grow in a controlled manner.

Mutations in the Retinoblastoma gene can lead to retinoblastoma, a rare type of eye cancer that typically affects young children. There are two types of retinoblastoma: hereditary and non-hereditary. Hereditary retinoblastoma is caused by an inherited mutation in the RB1 gene, while non-hereditary retinoblastoma is caused by a mutation that occurs spontaneously during development.

When both copies of the RB1 gene are mutated or inactivated in a retinal cell, it can lead to uncontrolled cell growth and division, resulting in the formation of a tumor. Symptoms of retinoblastoma may include an unusual white pupil reflex, crossed eyes, or a lazy eye. If left untreated, retinoblastoma can spread to other parts of the body and be life-threatening.

It is important to note that mutations in the RB1 gene can also increase the risk of developing other types of cancer, such as lung, breast, and bladder cancer, later in life.

A two-hybrid system technique is a type of genetic screening method used in molecular biology to identify protein-protein interactions within an organism, most commonly baker's yeast (Saccharomyces cerevisiae) or Escherichia coli. The name "two-hybrid" refers to the fact that two separate proteins are being examined for their ability to interact with each other.

The technique is based on the modular nature of transcription factors, which typically consist of two distinct domains: a DNA-binding domain (DBD) and an activation domain (AD). In a two-hybrid system, one protein of interest is fused to the DBD, while the second protein of interest is fused to the AD. If the two proteins interact, the DBD and AD are brought in close proximity, allowing for transcriptional activation of a reporter gene that is linked to a specific promoter sequence recognized by the DBD.

The main components of a two-hybrid system include:

1. Bait protein (fused to the DNA-binding domain)
2. Prey protein (fused to the activation domain)
3. Reporter gene (transcribed upon interaction between bait and prey proteins)
4. Promoter sequence (recognized by the DBD when brought in proximity due to interaction)

The two-hybrid system technique has several advantages, including:

1. Ability to screen large libraries of potential interacting partners
2. High sensitivity for detecting weak or transient interactions
3. Applicability to various organisms and protein types
4. Potential for high-throughput analysis

However, there are also limitations to the technique, such as false positives (interactions that do not occur in vivo) and false negatives (lack of detection of true interactions). Additionally, the fusion proteins may not always fold or localize correctly, leading to potential artifacts. Despite these limitations, two-hybrid system techniques remain a valuable tool for studying protein-protein interactions and have contributed significantly to our understanding of various cellular processes.

"Xenopus" is not a medical term, but it is a genus of highly invasive aquatic frogs native to sub-Saharan Africa. They are often used in scientific research, particularly in developmental biology and genetics. The most commonly studied species is Xenopus laevis, also known as the African clawed frog.

In a medical context, Xenopus might be mentioned when discussing their use in research or as a model organism to study various biological processes or diseases.

Northern blotting is a laboratory technique used in molecular biology to detect and analyze specific RNA molecules (such as mRNA) in a mixture of total RNA extracted from cells or tissues. This technique is called "Northern" blotting because it is analogous to the Southern blotting method, which is used for DNA detection.

The Northern blotting procedure involves several steps:

1. Electrophoresis: The total RNA mixture is first separated based on size by running it through an agarose gel using electrical current. This separates the RNA molecules according to their length, with smaller RNA fragments migrating faster than larger ones.

2. Transfer: After electrophoresis, the RNA bands are denatured (made single-stranded) and transferred from the gel onto a nitrocellulose or nylon membrane using a technique called capillary transfer or vacuum blotting. This step ensures that the order and relative positions of the RNA fragments are preserved on the membrane, similar to how they appear in the gel.

3. Cross-linking: The RNA is then chemically cross-linked to the membrane using UV light or heat treatment, which helps to immobilize the RNA onto the membrane and prevent it from washing off during subsequent steps.

4. Prehybridization: Before adding the labeled probe, the membrane is prehybridized in a solution containing blocking agents (such as salmon sperm DNA or yeast tRNA) to minimize non-specific binding of the probe to the membrane.

5. Hybridization: A labeled nucleic acid probe, specific to the RNA of interest, is added to the prehybridization solution and allowed to hybridize (form base pairs) with its complementary RNA sequence on the membrane. The probe can be either a DNA or an RNA molecule, and it is typically labeled with a radioactive isotope (such as ³²P) or a non-radioactive label (such as digoxigenin).

6. Washing: After hybridization, the membrane is washed to remove unbound probe and reduce background noise. The washing conditions (temperature, salt concentration, and detergent concentration) are optimized based on the stringency required for specific hybridization.

7. Detection: The presence of the labeled probe is then detected using an appropriate method, depending on the type of label used. For radioactive probes, this typically involves exposing the membrane to X-ray film or a phosphorimager screen and analyzing the resulting image. For non-radioactive probes, detection can be performed using colorimetric, chemiluminescent, or fluorescent methods.

8. Data analysis: The intensity of the signal is quantified and compared to controls (such as housekeeping genes) to determine the relative expression level of the RNA of interest. This information can be used for various purposes, such as identifying differentially expressed genes in response to a specific treatment or comparing gene expression levels across different samples or conditions.

A precipitin test is a type of immunodiagnostic test used to detect and measure the presence of specific antibodies or antigens in a patient's serum. The test is based on the principle of antigen-antibody interaction, where the addition of an antigen to a solution containing its corresponding antibody results in the formation of an insoluble immune complex known as a precipitin.

In this test, a small amount of the patient's serum is added to a solution containing a known antigen or antibody. If the patient has antibodies or antigens that correspond to the added reagent, they will bind and form a visible precipitate. The size and density of the precipitate can be used to quantify the amount of antibody or antigen present in the sample.

Precipitin tests are commonly used in the diagnosis of various infectious diseases, autoimmune disorders, and allergies. They can also be used in forensic science to identify biological samples. However, they have largely been replaced by more modern immunological techniques such as enzyme-linked immunosorbent assays (ELISAs) and radioimmunoassays (RIAs).

Chromosome segregation is the process that occurs during cell division (mitosis or meiosis) where replicated chromosomes are separated and distributed equally into two daughter cells. Each chromosome consists of two sister chromatids, which are identical copies of genetic material. During chromosome segregation, these sister chromatids are pulled apart by a structure called the mitotic spindle and moved to opposite poles of the cell. This ensures that each new cell receives one copy of each chromosome, preserving the correct number and composition of chromosomes in the organism.

"Cell count" is a medical term that refers to the process of determining the number of cells present in a given volume or sample of fluid or tissue. This can be done through various laboratory methods, such as counting individual cells under a microscope using a specialized grid called a hemocytometer, or using automated cell counters that use light scattering and electrical impedance techniques to count and classify different types of cells.

Cell counts are used in a variety of medical contexts, including hematology (the study of blood and blood-forming tissues), microbiology (the study of microscopic organisms), and pathology (the study of diseases and their causes). For example, a complete blood count (CBC) is a routine laboratory test that includes a white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin level, hematocrit value, and platelet count. Abnormal cell counts can indicate the presence of various medical conditions, such as infections, anemia, or leukemia.

Purines are heterocyclic aromatic organic compounds that consist of a pyrimidine ring fused to an imidazole ring. They are fundamental components of nucleotides, which are the building blocks of DNA and RNA. In the body, purines can be synthesized endogenously or obtained through dietary sources such as meat, seafood, and certain vegetables.

Once purines are metabolized, they are broken down into uric acid, which is excreted by the kidneys. Elevated levels of uric acid in the body can lead to the formation of uric acid crystals, resulting in conditions such as gout or kidney stones. Therefore, maintaining a balanced intake of purine-rich foods and ensuring proper kidney function are essential for overall health.

Caspases are a family of protease enzymes that play essential roles in programmed cell death, also known as apoptosis. These enzymes are produced as inactive precursors and are activated when cells receive signals to undergo apoptosis. Once activated, caspases cleave specific protein substrates, leading to the characteristic morphological changes and DNA fragmentation associated with apoptotic cell death. Caspases also play roles in other cellular processes, including inflammation and differentiation. There are two types of caspases: initiator caspases (caspase-2, -8, -9, and -10) and effector caspases (caspase-3, -6, and -7). Initiator caspases are activated in response to various apoptotic signals and then activate the effector caspases, which carry out the proteolytic cleavage of cellular proteins. Dysregulation of caspase activity has been implicated in a variety of diseases, including neurodegenerative disorders, ischemic injury, and cancer.

Protein kinase inhibitors (PKIs) are a class of drugs that work by interfering with the function of protein kinases. Protein kinases are enzymes that play a crucial role in many cellular processes by adding a phosphate group to specific proteins, thereby modifying their activity, localization, or interaction with other molecules. This process of adding a phosphate group is known as phosphorylation and is a key mechanism for regulating various cellular functions, including signal transduction, metabolism, and cell division.

In some diseases, such as cancer, protein kinases can become overactive or mutated, leading to uncontrolled cell growth and division. Protein kinase inhibitors are designed to block the activity of these dysregulated kinases, thereby preventing or slowing down the progression of the disease. These drugs can be highly specific, targeting individual protein kinases or families of kinases, making them valuable tools for targeted therapy in cancer and other diseases.

Protein kinase inhibitors can work in various ways to block the activity of protein kinases. Some bind directly to the active site of the enzyme, preventing it from interacting with its substrates. Others bind to allosteric sites, changing the conformation of the enzyme and making it inactive. Still, others target upstream regulators of protein kinases or interfere with their ability to form functional complexes.

Examples of protein kinase inhibitors include imatinib (Gleevec), which targets the BCR-ABL kinase in chronic myeloid leukemia, and gefitinib (Iressa), which inhibits the EGFR kinase in non-small cell lung cancer. These drugs have shown significant clinical benefits in treating these diseases and have become important components of modern cancer therapy.

BCL-2-associated X protein, often abbreviated as BAX, is a type of protein belonging to the BCL-2 family. The BCL-2 family of proteins plays a crucial role in regulating programmed cell death, also known as apoptosis. Specifically, BAX is a pro-apoptotic protein, which means that it promotes cell death.

BAX is encoded by the BAX gene, and it functions by forming pores in the outer membrane of the mitochondria, leading to the release of cytochrome c and other pro-apoptotic factors into the cytosol. This triggers a cascade of events that ultimately leads to cell death.

Dysregulation of BAX and other BCL-2 family proteins has been implicated in various diseases, including cancer and neurodegenerative disorders. For example, reduced levels of BAX have been observed in some types of cancer, which may contribute to tumor growth and resistance to chemotherapy. On the other hand, excessive activation of BAX has been linked to neuronal death in conditions such as Alzheimer's disease and Parkinson's disease.

Acetylation is a chemical process that involves the addition of an acetyl group (-COCH3) to a molecule. In the context of medical biochemistry, acetylation often refers to the post-translational modification of proteins, where an acetyl group is added to the amino group of a lysine residue in a protein by an enzyme called acetyltransferase. This modification can alter the function or stability of the protein and plays a crucial role in regulating various cellular processes such as gene expression, DNA repair, and cell signaling. Acetylation can also occur on other types of molecules, including lipids and carbohydrates, and has important implications for drug metabolism and toxicity.

"Drosophila" is a genus of small flies, also known as fruit flies. The most common species used in scientific research is "Drosophila melanogaster," which has been a valuable model organism for many areas of biological and medical research, including genetics, developmental biology, neurobiology, and aging.

The use of Drosophila as a model organism has led to numerous important discoveries in genetics and molecular biology, such as the identification of genes that are associated with human diseases like cancer, Parkinson's disease, and obesity. The short reproductive cycle, large number of offspring, and ease of genetic manipulation make Drosophila a powerful tool for studying complex biological processes.

The nucleolus is a structure found within the nucleus of eukaryotic cells (cells that contain a true nucleus). It plays a central role in the production and assembly of ribosomes, which are complex molecular machines responsible for protein synthesis. The nucleolus is not a distinct organelle with a membrane surrounding it, but rather a condensed region within the nucleus where ribosomal biogenesis takes place.

The process of ribosome formation begins in the nucleolus with the transcription of ribosomal DNA (rDNA) genes into long precursor RNA molecules called rRNAs (ribosomal RNAs). Within the nucleolus, these rRNA molecules are cleaved, modified, and assembled together with ribosomal proteins to form small and large ribosomal subunits. Once formed, these subunits are transported through the nuclear pores to the cytoplasm, where they come together to form functional ribosomes that can engage in protein synthesis.

In addition to its role in ribosome biogenesis, the nucleolus has been implicated in other cellular processes such as stress response, cell cycle regulation, and aging. Changes in nucleolar structure and function have been associated with various diseases, including cancer and neurodegenerative disorders.

Protein biosynthesis is the process by which cells generate new proteins. It involves two major steps: transcription and translation. Transcription is the process of creating a complementary RNA copy of a sequence of DNA. This RNA copy, or messenger RNA (mRNA), carries the genetic information to the site of protein synthesis, the ribosome. During translation, the mRNA is read by transfer RNA (tRNA) molecules, which bring specific amino acids to the ribosome based on the sequence of nucleotides in the mRNA. The ribosome then links these amino acids together in the correct order to form a polypeptide chain, which may then fold into a functional protein. Protein biosynthesis is essential for the growth and maintenance of all living organisms.

Protein-Tyrosine Kinases (PTKs) are a type of enzyme that plays a crucial role in various cellular functions, including signal transduction, cell growth, differentiation, and metabolism. They catalyze the transfer of a phosphate group from ATP to the tyrosine residues of proteins, thereby modifying their activity, localization, or interaction with other molecules.

PTKs can be divided into two main categories: receptor tyrosine kinases (RTKs) and non-receptor tyrosine kinases (NRTKs). RTKs are transmembrane proteins that become activated upon binding to specific ligands, such as growth factors or hormones. NRTKs, on the other hand, are intracellular enzymes that can be activated by various signals, including receptor-mediated signaling and intracellular messengers.

Dysregulation of PTK activity has been implicated in several diseases, such as cancer, diabetes, and inflammatory disorders. Therefore, PTKs are important targets for drug development and therapy.

Mitogen-Activated Protein Kinases (MAPKs) are a family of serine/threonine protein kinases that play crucial roles in various cellular processes, including proliferation, differentiation, transformation, and apoptosis, in response to diverse stimuli such as mitogens, growth factors, hormones, cytokines, and environmental stresses. They are highly conserved across eukaryotes and consist of a three-tiered kinase module composed of MAPK kinase kinases (MAP3Ks), MAPK kinases (MKKs or MAP2Ks), and MAPKs.

Activation of MAPKs occurs through a sequential phosphorylation and activation cascade, where MAP3Ks phosphorylate and activate MKKs, which in turn phosphorylate and activate MAPKs at specific residues (Thr-X-Tyr or Ser-Pro motifs). Once activated, MAPKs can further phosphorylate and regulate various downstream targets, including transcription factors and other protein kinases.

There are four major groups of MAPKs in mammals: extracellular signal-regulated kinases (ERK1/2), c-Jun N-terminal kinases (JNK1/2/3), p38 MAPKs (p38α/β/γ/δ), and ERK5/BMK1. Each group of MAPKs has distinct upstream activators, downstream targets, and cellular functions, allowing for a high degree of specificity in signal transduction and cellular responses. Dysregulation of MAPK signaling pathways has been implicated in various human diseases, including cancer, diabetes, neurodegenerative disorders, and inflammatory diseases.

Gene expression regulation, enzymologic refers to the biochemical processes and mechanisms that control the transcription and translation of specific genes into functional proteins or enzymes. This regulation is achieved through various enzymatic activities that can either activate or repress gene expression at different levels, such as chromatin remodeling, transcription factor activation, mRNA processing, and protein degradation.

Enzymologic regulation of gene expression involves the action of specific enzymes that catalyze chemical reactions involved in these processes. For example, histone-modifying enzymes can alter the structure of chromatin to make genes more or less accessible for transcription, while RNA polymerase and its associated factors are responsible for transcribing DNA into mRNA. Additionally, various enzymes are involved in post-transcriptional modifications of mRNA, such as splicing, capping, and tailing, which can affect the stability and translation of the transcript.

Overall, the enzymologic regulation of gene expression is a complex and dynamic process that allows cells to respond to changes in their environment and maintain proper physiological function.

Mitogen-activated protein kinase (MAPK) signaling system is a crucial pathway for the transmission and regulation of various cellular responses in eukaryotic cells. It plays a significant role in several biological processes, including proliferation, differentiation, apoptosis, inflammation, and stress response. The MAPK cascade consists of three main components: MAP kinase kinase kinase (MAP3K or MEKK), MAP kinase kinase (MAP2K or MEK), and MAP kinase (MAPK).

The signaling system is activated by various extracellular stimuli, such as growth factors, cytokines, hormones, and stress signals. These stimuli initiate a phosphorylation cascade that ultimately leads to the activation of MAPKs. The activated MAPKs then translocate into the nucleus and regulate gene expression by phosphorylating various transcription factors and other regulatory proteins.

There are four major MAPK families: extracellular signal-regulated kinases (ERK1/2), c-Jun N-terminal kinases (JNK1/2/3), p38 MAPKs (p38α/β/γ/δ), and ERK5. Each family has distinct functions, substrates, and upstream activators. Dysregulation of the MAPK signaling system can lead to various diseases, including cancer, diabetes, cardiovascular diseases, and neurological disorders. Therefore, understanding the molecular mechanisms underlying this pathway is crucial for developing novel therapeutic strategies.

I'm sorry for any confusion, but "Genes, myc" is not a recognized medical term or abbreviation. It seems like there might be a misunderstanding or a missing word in the request. "Myc" could refer to the Myc family of transcription factors that are involved in cell growth and division, and are often deregulated in cancer. However, without more context, it's difficult to provide an accurate definition. If you could provide more information or clarify your question, I would be happy to help further!

Drug screening assays for antitumor agents are laboratory tests used to identify and evaluate the effectiveness of potential drugs or compounds that can inhibit the growth of tumor cells or induce their death. These assays are typically performed in vitro (in a test tube or petri dish) using cell cultures of various types of cancer cells.

The assays measure different parameters such as cell viability, proliferation, apoptosis (programmed cell death), and cytotoxicity to determine the ability of the drug to kill or inhibit the growth of tumor cells. The results of these assays can help researchers identify promising antitumor agents that can be further developed for clinical use in cancer treatment.

There are different types of drug screening assays for antitumor agents, including high-throughput screening (HTS) assays, which allow for the rapid and automated testing of a large number of compounds against various cancer cell lines. Other types of assays include phenotypic screening assays, target-based screening assays, and functional screening assays, each with its own advantages and limitations.

Overall, drug screening assays for antitumor agents play a critical role in the development of new cancer therapies by providing valuable information on the activity and safety of potential drugs, helping to identify effective treatments and reduce the time and cost associated with bringing new drugs to market.

Minichromosome Maintenance Complex Component 2 (MCM2) is a protein that is a part of the minichromosome maintenance (MCM) complex, which is involved in the initiation and regulation of DNA replication. MCM2 is specifically a helicase that helps to unwind the DNA double helix during replication. It is essential for the proper duplication of genetic material and cell division. Abnormalities in MCM2 function have been implicated in various diseases, including cancer.

Genomic instability is a term used in genetics and molecular biology to describe a state of increased susceptibility to genetic changes or mutations in the genome. It can be defined as a condition where the integrity and stability of the genome are compromised, leading to an increased rate of DNA alterations such as point mutations, insertions, deletions, and chromosomal rearrangements.

Genomic instability is a hallmark of cancer cells and can also be observed in various other diseases, including genetic disorders and aging. It can arise due to defects in the DNA repair mechanisms, telomere maintenance, epigenetic regulation, or chromosome segregation during cell division. These defects can result from inherited genetic mutations, acquired somatic mutations, exposure to environmental mutagens, or age-related degenerative changes.

Genomic instability is a significant factor in the development and progression of cancer as it promotes the accumulation of oncogenic mutations that contribute to tumor initiation, growth, and metastasis. Therefore, understanding the mechanisms underlying genomic instability is crucial for developing effective strategies for cancer prevention, diagnosis, and treatment.

Colonic neoplasms refer to abnormal growths in the large intestine, also known as the colon. These growths can be benign (non-cancerous) or malignant (cancerous). The two most common types of colonic neoplasms are adenomas and carcinomas.

Adenomas are benign tumors that can develop into cancer over time if left untreated. They are often found during routine colonoscopies and can be removed during the procedure.

Carcinomas, on the other hand, are malignant tumors that invade surrounding tissues and can spread to other parts of the body. Colorectal cancer is the third leading cause of cancer-related deaths in the United States, and colonic neoplasms are a significant risk factor for developing this type of cancer.

Regular screenings for colonic neoplasms are recommended for individuals over the age of 50 or those with a family history of colorectal cancer or other risk factors. Early detection and removal of colonic neoplasms can significantly reduce the risk of developing colorectal cancer.

Cyclin-Dependent Kinase Inhibitor p15, also known as CDKN2B or INK4b, is a protein that regulates the cell cycle. It inhibits the activity of cyclin-dependent kinases (CDKs), specifically the CDK4 and CDK6 complexes with cyclin D, which play a crucial role in regulating the progression of the cell cycle from the G1 phase to the S phase.

The p15 protein is encoded by the CDKN2B gene, which is located on human chromosome 9p21. The expression of the CDKN2B gene is induced by various signals, including DNA damage and differentiation signals, leading to the inhibition of CDK4/6-cyclin D complexes and cell cycle arrest in the G1 phase. This provides an essential mechanism for preventing cells with damaged DNA from entering the S phase and undergoing DNA replication, thereby ensuring genomic stability and preventing tumorigenesis.

Mutations or deletions of the CDKN2B gene have been implicated in various human cancers, including gliomas, melanomas, and leukemias, suggesting that the loss of p15 function may contribute to tumor development and progression.

An ovary is a part of the female reproductive system in which ova or eggs are produced through the process of oogenesis. They are a pair of solid, almond-shaped structures located one on each side of the uterus within the pelvic cavity. Each ovary measures about 3 to 5 centimeters in length and weighs around 14 grams.

The ovaries have two main functions: endocrine (hormonal) function and reproductive function. They produce and release eggs (ovulation) responsible for potential fertilization and development of an embryo/fetus during pregnancy. Additionally, they are essential in the production of female sex hormones, primarily estrogen and progesterone, which regulate menstrual cycles, sexual development, and reproduction.

During each menstrual cycle, a mature egg is released from one of the ovaries into the fallopian tube, where it may be fertilized by sperm. If not fertilized, the egg, along with the uterine lining, will be shed, leading to menstruation.

Cyclin-Dependent Kinase Inhibitor p19, also known as CDKN2A or INK4a, is a protein that functions as a tumor suppressor. It inhibits the activity of cyclin-dependent kinases (CDKs), which are enzymes that play crucial roles in regulating the cell cycle.

The cell cycle is a series of events that cells undergo as they grow and divide. CDKs help to control the progression of the cell cycle by phosphorylating various target proteins, including other CDKs and proteins involved in DNA replication and mitosis.

Cyclin-Dependent Kinase Inhibitor p19 inhibits CDK4 and CDK6, which are important regulators of the G1 phase of the cell cycle. By inhibiting these kinases, p19 helps to prevent the premature entry of cells into the S phase of the cell cycle, where DNA replication occurs.

Mutations in the gene that encodes Cyclin-Dependent Kinase Inhibitor p19 have been associated with several types of cancer, including melanoma, pancreatic cancer, and lung cancer. These mutations can lead to the loss or reduction of p19 function, which can contribute to uncontrolled cell growth and tumor formation.

Ubiquitin is a small protein that is present in all eukaryotic cells and plays a crucial role in the regulation of various cellular processes, such as protein degradation, DNA repair, and stress response. It is involved in marking proteins for destruction by attaching to them, a process known as ubiquitination. This modification can target proteins for degradation by the proteasome, a large protein complex that breaks down unneeded or damaged proteins in the cell. Ubiquitin also has other functions, such as regulating the localization and activity of certain proteins. The ability of ubiquitin to modify many different proteins and play a role in multiple cellular processes makes it an essential player in maintaining cellular homeostasis.

Doxorubicin is a type of chemotherapy medication known as an anthracycline. It works by interfering with the DNA in cancer cells, which prevents them from growing and multiplying. Doxorubicin is used to treat a wide variety of cancers, including leukemia, lymphoma, breast cancer, lung cancer, ovarian cancer, and many others. It may be given alone or in combination with other chemotherapy drugs.

Doxorubicin is usually administered through a vein (intravenously) and can cause side effects such as nausea, vomiting, hair loss, mouth sores, and increased risk of infection. It can also cause damage to the heart muscle, which can lead to heart failure in some cases. For this reason, doctors may monitor patients' heart function closely while they are receiving doxorubicin treatment.

It is important for patients to discuss the potential risks and benefits of doxorubicin therapy with their healthcare provider before starting treatment.

I'm sorry for any confusion, but "Protamine Kinase" is not a widely recognized or established term in medical or biological sciences. Protamines are small, arginine-rich proteins found in the sperm cells of many organisms, and they play a crucial role in the packaging and protection of DNA during spermatogenesis.

Kinases, on the other hand, are enzymes that catalyze the transfer of phosphate groups from ATP to specific amino acids in proteins, thereby modulating their function, localization, or stability.

A search of scientific literature reveals only a few instances where "protamine kinase" is mentioned, usually in the context of potential regulatory mechanisms during sperm maturation or fertilization. However, there is no widely accepted or well-characterized enzyme known as "protamine kinase." Therefore, it would be challenging to provide a concise and accurate medical definition for this term.

A "reporter gene" is a type of gene that is linked to a gene of interest in order to make the expression or activity of that gene detectable. The reporter gene encodes for a protein that can be easily measured and serves as an indicator of the presence and activity of the gene of interest. Commonly used reporter genes include those that encode for fluorescent proteins, enzymes that catalyze colorimetric reactions, or proteins that bind to specific molecules.

In the context of genetics and genomics research, a reporter gene is often used in studies involving gene expression, regulation, and function. By introducing the reporter gene into an organism or cell, researchers can monitor the activity of the gene of interest in real-time or after various experimental treatments. The information obtained from these studies can help elucidate the role of specific genes in biological processes and diseases, providing valuable insights for basic research and therapeutic development.

The luteal phase is the second half of the menstrual cycle, starting from ovulation (release of an egg from the ovaries) and lasting until the start of the next menstruation. This phase typically lasts around 12-14 days in a regular 28-day menstrual cycle. During this phase, the remains of the dominant follicle that released the egg transform into the corpus luteum, which produces progesterone and some estrogen to support the implantation of a fertilized egg and maintain the early stages of pregnancy. If pregnancy does not occur, the corpus luteum degenerates, leading to a drop in hormone levels and the start of a new menstrual cycle.

E2F5 is a member of the E2F family of transcription factors, which are involved in the regulation of cell cycle progression and differentiation. E2F5 can function as both a transcriptional activator and repressor, depending on whether it forms a complex with a retinoblastoma protein or not. When bound to a retinoblastoma protein, E2F5 acts as a transcriptional repressor, preventing the expression of genes required for cell cycle progression. However, when E2F5 is not bound to a retinoblastoma protein, it can act as a transcriptional activator and promote the expression of genes involved in differentiation and development.

E2F5 has been shown to play important roles in various biological processes, including cell growth, apoptosis, and tumor suppression. Mutations or dysregulation of E2F5 have been implicated in several human diseases, including cancer. Therefore, understanding the function and regulation of E2F5 is crucial for developing new therapeutic strategies to treat these diseases.

Anaphase is a stage in the cell division process called mitosis, where sister chromatids (the two copies of each chromosome formed during DNA replication) separate at the centromeres and move toward opposite poles of the cell. This separation is facilitated by the attachment of microtubules from the spindle apparatus to the kinetochores, protein structures located on the centromeres of each sister chromatid. Anaphase is followed by telophase, during which the nuclear membrane reforms around each set of separated chromosomes, and cytokinesis, the division of the cytoplasm to form two separate daughter cells.

The follicular phase is a term used in reproductive endocrinology, which refers to the first part of the menstrual cycle. This phase begins on the first day of menstruation and lasts until ovulation. During this phase, several follicles in the ovaries begin to mature under the influence of follicle-stimulating hormone (FSH) released by the pituitary gland.

Typically, one follicle becomes dominant and continues to mature, while the others regress. The dominant follicle produces increasing amounts of estrogen, which causes the lining of the uterus to thicken in preparation for a possible pregnancy. The follicular phase can vary in length, but on average it lasts about 14 days.

It's important to note that the length and characteristics of the follicular phase can provide valuable information in diagnosing various reproductive disorders, such as polycystic ovary syndrome (PCOS) or thyroid dysfunction.

Telophase is a phase in the cell division process (mitosis or meiosis) where the chromosomes reach their most condensed form and move to the poles of the cell. The nuclear membrane begins to reform around each set of chromosomes, and the spindle fibers that were used to separate the chromosomes break down. This phase is followed by cytokinesis, where the cytoplasm of the cell divides, resulting in two separate daughter cells. In telophase I of meiosis, crossing over between homologous chromosomes has already occurred during prophase I and sister chromatids remain together until anaphase II.

Cell separation is a process used to separate and isolate specific cell types from a heterogeneous mixture of cells. This can be accomplished through various physical or biological methods, depending on the characteristics of the cells of interest. Some common techniques for cell separation include:

1. Density gradient centrifugation: In this method, a sample containing a mixture of cells is layered onto a density gradient medium and then centrifuged. The cells are separated based on their size, density, and sedimentation rate, with denser cells settling closer to the bottom of the tube and less dense cells remaining near the top.

2. Magnetic-activated cell sorting (MACS): This technique uses magnetic beads coated with antibodies that bind to specific cell surface markers. The labeled cells are then passed through a column placed in a magnetic field, which retains the magnetically labeled cells while allowing unlabeled cells to flow through.

3. Fluorescence-activated cell sorting (FACS): In this method, cells are stained with fluorochrome-conjugated antibodies that recognize specific cell surface or intracellular markers. The stained cells are then passed through a laser beam, which excites the fluorophores and allows for the detection and sorting of individual cells based on their fluorescence profile.

4. Filtration: This simple method relies on the physical size differences between cells to separate them. Cells can be passed through filters with pore sizes that allow smaller cells to pass through while retaining larger cells.

5. Enzymatic digestion: In some cases, cells can be separated by enzymatically dissociating tissues into single-cell suspensions and then using various separation techniques to isolate specific cell types.

These methods are widely used in research and clinical settings for applications such as isolating immune cells, stem cells, or tumor cells from biological samples.

I'm sorry for any confusion, but "Active Transport, Cell Nucleus" is not a widely recognized or established medical term. Active transport typically refers to the energy-dependent process by which cells move molecules across their membranes against their concentration gradient. This process is facilitated by transport proteins and requires ATP as an energy source. However, this process primarily occurs in the cell membrane and not in the cell nucleus.

The cell nucleus, on the other hand, contains genetic material (DNA) and is responsible for controlling various cellular activities such as gene expression, replication, and repair. While there are transport processes that occur within the nucleus, they do not typically involve active transport in the same way that it occurs at the cell membrane.

Therefore, a medical definition of "Active Transport, Cell Nucleus" would not be applicable or informative in this context.

Membrane proteins are a type of protein that are embedded in the lipid bilayer of biological membranes, such as the plasma membrane of cells or the inner membrane of mitochondria. These proteins play crucial roles in various cellular processes, including:

1. Cell-cell recognition and signaling
2. Transport of molecules across the membrane (selective permeability)
3. Enzymatic reactions at the membrane surface
4. Energy transduction and conversion
5. Mechanosensation and signal transduction

Membrane proteins can be classified into two main categories: integral membrane proteins, which are permanently associated with the lipid bilayer, and peripheral membrane proteins, which are temporarily or loosely attached to the membrane surface. Integral membrane proteins can further be divided into three subcategories based on their topology:

1. Transmembrane proteins, which span the entire width of the lipid bilayer with one or more alpha-helices or beta-barrels.
2. Lipid-anchored proteins, which are covalently attached to lipids in the membrane via a glycosylphosphatidylinositol (GPI) anchor or other lipid modifications.
3. Monotopic proteins, which are partially embedded in the membrane and have one or more domains exposed to either side of the bilayer.

Membrane proteins are essential for maintaining cellular homeostasis and are targets for various therapeutic interventions, including drug development and gene therapy. However, their structural complexity and hydrophobicity make them challenging to study using traditional biochemical methods, requiring specialized techniques such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and single-particle cryo-electron microscopy (cryo-EM).

p14ARF is a tumor suppressor protein that plays a crucial role in regulating the cell cycle and preventing uncontrolled cell growth, which can lead to cancer. It is encoded by the CDKN2A gene located on chromosome 9p21.3. The p14ARF protein functions by binding to and inhibiting the activity of MDM2, a negative regulator of the tumor suppressor protein p53. By inhibiting MDM2, p14ARF promotes the stabilization and activation of p53, leading to cell cycle arrest or apoptosis in response to oncogenic signals or DNA damage. Mutations or deletions in the CDKN2A gene can result in the loss of p14ARF function, contributing to tumorigenesis.

A zygote is the initial cell formed when a sperm fertilizes an egg, also known as an oocyte. This occurs in the process of human reproduction and marks the beginning of a new genetic identity, containing 46 chromosomes - 23 from the sperm and 23 from the egg. The zygote starts the journey of cell division and growth, eventually developing into a blastocyst, then an embryo, and finally a fetus over the course of pregnancy.

Time-lapse imaging is a medical imaging technique where images are captured at regular intervals over a period of time and then played back at a faster rate to show the progression or changes that occur during that time frame. This technique is often used in various fields of medicine, including microbiology, pathology, and reproductive medicine. In microbiology, for example, time-lapse imaging can be used to observe bacterial growth or the movement of individual cells. In pathology, it might help track the development of a lesion or the response of a tumor to treatment. In reproductive medicine, time-lapse imaging is commonly employed in embryo culture during in vitro fertilization (IVF) procedures to assess the development and quality of embryos before implantation.

Ubiquitination is a post-translational modification process in which a ubiquitin protein is covalently attached to a target protein. This process plays a crucial role in regulating various cellular functions, including protein degradation, DNA repair, and signal transduction. The addition of ubiquitin can lead to different outcomes depending on the number and location of ubiquitin molecules attached to the target protein. Monoubiquitination (the attachment of a single ubiquitin molecule) or multiubiquitination (the attachment of multiple ubiquitin molecules) can mark proteins for degradation by the 26S proteasome, while specific types of ubiquitination (e.g., K63-linked polyubiquitination) can serve as a signal for nonproteolytic functions such as endocytosis, autophagy, or DNA repair. Ubiquitination is a highly regulated process that involves the coordinated action of three enzymes: E1 ubiquitin-activating enzyme, E2 ubiquitin-conjugating enzyme, and E3 ubiquitin ligase. Dysregulation of ubiquitination has been implicated in various diseases, including cancer, neurodegenerative disorders, and inflammatory conditions.

DNA fragmentation is the breaking of DNA strands into smaller pieces. This process can occur naturally during apoptosis, or programmed cell death, where the DNA is broken down and packaged into apoptotic bodies to be safely eliminated from the body. However, excessive or abnormal DNA fragmentation can also occur due to various factors such as oxidative stress, exposure to genotoxic agents, or certain medical conditions. This can lead to genetic instability, cellular dysfunction, and increased risk of diseases such as cancer. In the context of reproductive medicine, high levels of DNA fragmentation in sperm cells have been linked to male infertility and poor assisted reproductive technology outcomes.

Cisplatin is a chemotherapeutic agent used to treat various types of cancers, including testicular, ovarian, bladder, head and neck, lung, and cervical cancers. It is an inorganic platinum compound that contains a central platinum atom surrounded by two chloride atoms and two ammonia molecules in a cis configuration.

Cisplatin works by forming crosslinks between DNA strands, which disrupts the structure of DNA and prevents cancer cells from replicating. This ultimately leads to cell death and slows down or stops the growth of tumors. However, cisplatin can also cause damage to normal cells, leading to side effects such as nausea, vomiting, hearing loss, and kidney damage. Therefore, it is essential to monitor patients closely during treatment and manage any adverse effects promptly.

Ligases are a group of enzymes that catalyze the formation of a covalent bond between two molecules, usually involving the joining of two nucleotides in a DNA or RNA strand. They play a crucial role in various biological processes such as DNA replication, repair, and recombination. In DNA ligases, the enzyme seals nicks or breaks in the phosphodiester backbone of the DNA molecule by catalyzing the formation of an ester bond between the 3'-hydroxyl group and the 5'-phosphate group of adjacent nucleotides. This process is essential for maintaining genomic integrity and stability.

Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify specific regions of DNA. It enables the production of thousands to millions of copies of a particular DNA sequence in a rapid and efficient manner, making it an essential tool in various fields such as molecular biology, medical diagnostics, forensic science, and research.

The PCR process involves repeated cycles of heating and cooling to separate the DNA strands, allow primers (short sequences of single-stranded DNA) to attach to the target regions, and extend these primers using an enzyme called Taq polymerase, resulting in the exponential amplification of the desired DNA segment.

In a medical context, PCR is often used for detecting and quantifying specific pathogens (viruses, bacteria, fungi, or parasites) in clinical samples, identifying genetic mutations or polymorphisms associated with diseases, monitoring disease progression, and evaluating treatment effectiveness.

Ubiquitin is a small protein that is present in most tissues in the body. It plays a critical role in regulating many important cellular processes, such as protein degradation and DNA repair. Ubiquitin can attach to other proteins in a process called ubiquitination, which can target the protein for degradation or modify its function.

Ubiquitination involves a series of enzymatic reactions that ultimately result in the attachment of ubiquitin molecules to specific lysine residues on the target protein. The addition of a single ubiquitin molecule is called monoubiquitination, while the addition of multiple ubiquitin molecules is called polyubiquitination.

Polyubiquitination can serve as a signal for proteasomal degradation, where the target protein is broken down into its component amino acids by the 26S proteasome complex. Monoubiquitination and other forms of ubiquitination can also regulate various cellular processes, such as endocytosis, DNA repair, and gene expression.

Dysregulation of ubiquitin-mediated protein degradation has been implicated in a variety of diseases, including cancer, neurodegenerative disorders, and inflammatory conditions.

MicroRNAs (miRNAs) are a class of small non-coding RNAs, typically consisting of around 20-24 nucleotides, that play crucial roles in post-transcriptional regulation of gene expression. They primarily bind to the 3' untranslated region (3' UTR) of target messenger RNAs (mRNAs), leading to mRNA degradation or translational repression. MicroRNAs are involved in various biological processes, including development, differentiation, proliferation, and apoptosis, and have been implicated in numerous diseases, such as cancers and neurological disorders. They can be found in various organisms, from plants to animals, and are often conserved across species. MicroRNAs are usually transcribed from DNA sequences located in introns or exons of protein-coding genes or in intergenic regions. After transcription, they undergo a series of processing steps, including cleavage by ribonucleases Drosha and Dicer, to generate mature miRNA molecules capable of binding to their target mRNAs.

Mutagenesis is the process by which the genetic material (DNA or RNA) of an organism is changed in a way that can alter its phenotype, or observable traits. These changes, known as mutations, can be caused by various factors such as chemicals, radiation, or viruses. Some mutations may have no effect on the organism, while others can cause harm, including diseases and cancer. Mutagenesis is a crucial area of study in genetics and molecular biology, with implications for understanding evolution, genetic disorders, and the development of new medical treatments.

Phosphatidylinositol 3-Kinases (PI3Ks) are a family of enzymes that play a crucial role in intracellular signal transduction. They phosphorylate the 3-hydroxyl group of the inositol ring in phosphatidylinositol and its derivatives, which results in the production of second messengers that regulate various cellular processes such as cell growth, proliferation, differentiation, motility, and survival.

PI3Ks are divided into three classes based on their structure and substrate specificity. Class I PI3Ks are further subdivided into two categories: class IA and class IB. Class IA PI3Ks are heterodimers consisting of a catalytic subunit (p110α, p110β, or p110δ) and a regulatory subunit (p85α, p85β, p55γ, or p50γ). They are primarily activated by receptor tyrosine kinases and G protein-coupled receptors. Class IB PI3Ks consist of a catalytic subunit (p110γ) and a regulatory subunit (p101 or p84/87). They are mainly activated by G protein-coupled receptors.

Dysregulation of PI3K signaling has been implicated in various human diseases, including cancer, diabetes, and autoimmune disorders. Therefore, PI3Ks have emerged as important targets for drug development in these areas.

Keratinocytes are the predominant type of cells found in the epidermis, which is the outermost layer of the skin. These cells are responsible for producing keratin, a tough protein that provides structural support and protection to the skin. Keratinocytes undergo constant turnover, with new cells produced in the basal layer of the epidermis and older cells moving upward and eventually becoming flattened and filled with keratin as they reach the surface of the skin, where they are then shed. They also play a role in the immune response and can release cytokines and other signaling molecules to help protect the body from infection and injury.

Paclitaxel is a chemotherapeutic agent derived from the bark of the Pacific yew tree (Taxus brevifolia). It is an antimicrotubule agent that promotes the assembly and stabilization of microtubules, thereby interfering with the normal dynamic reorganization of the microtubule network that is essential for cell division.

Paclitaxel is used in the treatment of various types of cancer including ovarian, breast, lung, and pancreatic cancers. It works by inhibiting the disassembly of microtubules, which prevents the separation of chromosomes during mitosis, leading to cell cycle arrest and apoptosis (programmed cell death).

Common side effects of paclitaxel include neutropenia (low white blood cell count), anemia (low red blood cell count), alopecia (hair loss), peripheral neuropathy (nerve damage causing numbness or tingling in the hands and feet), myalgias (muscle pain), arthralgias (joint pain), and hypersensitivity reactions.

An ovum is the female reproductive cell, or gamete, produced in the ovaries. It is also known as an egg cell and is released from the ovary during ovulation. When fertilized by a sperm, it becomes a zygote, which can develop into a fetus. The ovum contains half the genetic material necessary to create a new individual.

A circadian rhythm is a roughly 24-hour biological cycle that regulates various physiological and behavioral processes in living organisms. It is driven by the body's internal clock, which is primarily located in the suprachiasmatic nucleus (SCN) of the hypothalamus in the brain.

The circadian rhythm controls many aspects of human physiology, including sleep-wake cycles, hormone secretion, body temperature, and metabolism. It helps to synchronize these processes with the external environment, particularly the day-night cycle caused by the rotation of the Earth.

Disruptions to the circadian rhythm can have negative effects on health, leading to conditions such as insomnia, sleep disorders, depression, bipolar disorder, and even increased risk of chronic diseases like cancer, diabetes, and cardiovascular disease. Factors that can disrupt the circadian rhythm include shift work, jet lag, irregular sleep schedules, and exposure to artificial light at night.

RNA (Ribonucleic Acid) is a single-stranded, linear polymer of ribonucleotides. It is a nucleic acid present in the cells of all living organisms and some viruses. RNAs play crucial roles in various biological processes such as protein synthesis, gene regulation, and cellular signaling. There are several types of RNA including messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), small nuclear RNA (snRNA), microRNA (miRNA), and long non-coding RNA (lncRNA). These RNAs differ in their structure, function, and location within the cell.

Lung neoplasms refer to abnormal growths or tumors in the lung tissue. These tumors can be benign (non-cancerous) or malignant (cancerous). Malignant lung neoplasms are further classified into two main types: small cell lung carcinoma and non-small cell lung carcinoma. Lung neoplasms can cause symptoms such as cough, chest pain, shortness of breath, and weight loss. They are often caused by smoking or exposure to secondhand smoke, but can also occur due to genetic factors, radiation exposure, and other environmental carcinogens. Early detection and treatment of lung neoplasms is crucial for improving outcomes and survival rates.

Yeasts are single-celled microorganisms that belong to the fungus kingdom. They are characterized by their ability to reproduce asexually through budding or fission, and they obtain nutrients by fermenting sugars and other organic compounds. Some species of yeast can cause infections in humans, known as candidiasis or "yeast infections." These infections can occur in various parts of the body, including the skin, mouth, genitals, and internal organs. Common symptoms of a yeast infection may include itching, redness, irritation, and discharge. Yeast infections are typically treated with antifungal medications.

Maturation-Promoting Factor (MPF) is not a medical term per se, but it is commonly used in the field of cell biology and cancer research. MPF refers to a complex of two proteins that play a crucial role in regulating the cell cycle, specifically during the transition from the G2 phase to mitosis (M phase).

MPF is composed of a cyclin-dependent kinase (CDK1) and a regulatory subunit called cyclin B. During the late G2 phase, the levels of cyclin B increase, which leads to the activation of CDK1. Once activated, MPF triggers a series of events that promote mitosis, including chromosome condensation, nuclear envelope breakdown, and spindle formation.

In summary, Maturation-Promoting Factor (MPF) is a protein complex made up of CDK1 and cyclin B, which regulates the transition from the G2 phase to mitosis during the cell cycle.

Cullin proteins are a family of structurally related proteins that play a crucial role in the function of E3 ubiquitin ligase complexes. These complexes are responsible for targeting specific cellular proteins for degradation by the proteasome, which is a key process in maintaining protein homeostasis within cells.

Cullin proteins act as scaffolds that bring together different components of the E3 ubiquitin ligase complex, including RING finger proteins and substrate receptors. There are several different cullin proteins identified in humans (CUL1, CUL2, CUL3, CUL4A, CUL4B, CUL5, and CUL7), each of which can form distinct E3 ubiquitin ligase complexes with unique substrate specificities.

The regulation of cullin proteins is critical for normal cellular function, and dysregulation of these proteins has been implicated in various diseases, including cancer. For example, mutations in CUL1 have been found in certain types of breast and ovarian cancers, while alterations in CUL3 have been linked to neurodegenerative disorders such as Parkinson's disease.

Overall, cullin proteins are essential components of the ubiquitin-proteasome system, which plays a critical role in regulating protein turnover and maintaining cellular homeostasis.

Drug synergism is a pharmacological concept that refers to the interaction between two or more drugs, where the combined effect of the drugs is greater than the sum of their individual effects. This means that when these drugs are administered together, they produce an enhanced therapeutic response compared to when they are given separately.

Drug synergism can occur through various mechanisms, such as:

1. Pharmacodynamic synergism - When two or more drugs interact with the same target site in the body and enhance each other's effects.
2. Pharmacokinetic synergism - When one drug affects the metabolism, absorption, distribution, or excretion of another drug, leading to an increased concentration of the second drug in the body and enhanced therapeutic effect.
3. Physiochemical synergism - When two drugs interact physically, such as when one drug enhances the solubility or permeability of another drug, leading to improved absorption and bioavailability.

It is important to note that while drug synergism can result in enhanced therapeutic effects, it can also increase the risk of adverse reactions and toxicity. Therefore, healthcare providers must carefully consider the potential benefits and risks when prescribing combinations of drugs with known or potential synergistic effects.

A replication origin is a specific location in a DNA molecule where the process of DNA replication is initiated. It serves as the starting point for the synthesis of new strands of DNA during cell division. The origin of replication contains regulatory elements and sequences that are recognized by proteins, which then recruit and assemble the necessary enzymes to start the replication process. In eukaryotic cells, replication origins are often found in clusters, with multiple origins scattered throughout each chromosome.

Neurons, also known as nerve cells or neurocytes, are specialized cells that constitute the basic unit of the nervous system. They are responsible for receiving, processing, and transmitting information and signals within the body. Neurons have three main parts: the dendrites, the cell body (soma), and the axon. The dendrites receive signals from other neurons or sensory receptors, while the axon transmits these signals to other neurons, muscles, or glands. The junction between two neurons is called a synapse, where neurotransmitters are released to transmit the signal across the gap (synaptic cleft) to the next neuron. Neurons vary in size, shape, and structure depending on their function and location within the nervous system.

Genetic models are theoretical frameworks used in genetics to describe and explain the inheritance patterns and genetic architecture of traits, diseases, or phenomena. These models are based on mathematical equations and statistical methods that incorporate information about gene frequencies, modes of inheritance, and the effects of environmental factors. They can be used to predict the probability of certain genetic outcomes, to understand the genetic basis of complex traits, and to inform medical management and treatment decisions.

There are several types of genetic models, including:

1. Mendelian models: These models describe the inheritance patterns of simple genetic traits that follow Mendel's laws of segregation and independent assortment. Examples include autosomal dominant, autosomal recessive, and X-linked inheritance.
2. Complex trait models: These models describe the inheritance patterns of complex traits that are influenced by multiple genes and environmental factors. Examples include heart disease, diabetes, and cancer.
3. Population genetics models: These models describe the distribution and frequency of genetic variants within populations over time. They can be used to study evolutionary processes, such as natural selection and genetic drift.
4. Quantitative genetics models: These models describe the relationship between genetic variation and phenotypic variation in continuous traits, such as height or IQ. They can be used to estimate heritability and to identify quantitative trait loci (QTLs) that contribute to trait variation.
5. Statistical genetics models: These models use statistical methods to analyze genetic data and infer the presence of genetic associations or linkage. They can be used to identify genetic risk factors for diseases or traits.

Overall, genetic models are essential tools in genetics research and medical genetics, as they allow researchers to make predictions about genetic outcomes, test hypotheses about the genetic basis of traits and diseases, and develop strategies for prevention, diagnosis, and treatment.

Mitochondria are specialized structures located inside cells that convert the energy from food into ATP (adenosine triphosphate), which is the primary form of energy used by cells. They are often referred to as the "powerhouses" of the cell because they generate most of the cell's supply of chemical energy. Mitochondria are also involved in various other cellular processes, such as signaling, differentiation, and apoptosis (programmed cell death).

Mitochondria have their own DNA, known as mitochondrial DNA (mtDNA), which is inherited maternally. This means that mtDNA is passed down from the mother to her offspring through the egg cells. Mitochondrial dysfunction has been linked to a variety of diseases and conditions, including neurodegenerative disorders, diabetes, and aging.

Confocal microscopy is a powerful imaging technique used in medical and biological research to obtain high-resolution, contrast-rich images of thick samples. This super-resolution technology provides detailed visualization of cellular structures and processes at various depths within a specimen.

In confocal microscopy, a laser beam focused through a pinhole illuminates a small spot within the sample. The emitted fluorescence or reflected light from this spot is then collected by a detector, passing through a second pinhole that ensures only light from the focal plane reaches the detector. This process eliminates out-of-focus light, resulting in sharp images with improved contrast compared to conventional widefield microscopy.

By scanning the laser beam across the sample in a raster pattern and collecting fluorescence at each point, confocal microscopy generates optical sections of the specimen. These sections can be combined to create three-dimensional reconstructions, allowing researchers to study cellular architecture and interactions within complex tissues.

Confocal microscopy has numerous applications in medical research, including studying protein localization, tracking intracellular dynamics, analyzing cell morphology, and investigating disease mechanisms at the cellular level. Additionally, it is widely used in clinical settings for diagnostic purposes, such as analyzing skin lesions or detecting pathogens in patient samples.

Indole is not strictly a medical term, but it is a chemical compound that can be found in the human body and has relevance to medical and biological research. Indoles are organic compounds that contain a bicyclic structure consisting of a six-membered benzene ring fused to a five-membered pyrrole ring.

In the context of medicine, indoles are particularly relevant due to their presence in certain hormones and other biologically active molecules. For example, the neurotransmitter serotonin contains an indole ring, as does the hormone melatonin. Indoles can also be found in various plant-based foods, such as cruciferous vegetables (e.g., broccoli, kale), and have been studied for their potential health benefits.

Some indoles, like indole-3-carbinol and diindolylmethane, are found in these vegetables and can have anti-cancer properties by modulating estrogen metabolism, reducing inflammation, and promoting cell death (apoptosis) in cancer cells. However, it is essential to note that further research is needed to fully understand the potential health benefits and risks associated with indoles.

Fertilization in vitro, also known as in-vitro fertilization (IVF), is a medical procedure where an egg (oocyte) and sperm are combined in a laboratory dish to facilitate fertilization. The fertilized egg (embryo) is then transferred to a uterus with the hope of establishing a successful pregnancy. This procedure is often used when other assisted reproductive technologies have been unsuccessful or are not applicable, such as in cases of blocked fallopian tubes, severe male factor infertility, and unexplained infertility. The process involves ovarian stimulation, egg retrieval, fertilization, embryo culture, and embryo transfer. In some cases, additional techniques such as intracytoplasmic sperm injection (ICSI) or preimplantation genetic testing (PGT) may be used to increase the chances of success.

In situ nick-end labeling (ISEL, also known as TUNEL) is a technique used in pathology and molecular biology to detect DNA fragmentation, which is a characteristic of apoptotic cells (cells undergoing programmed cell death). The method involves labeling the 3'-hydroxyl termini of double or single stranded DNA breaks in situ (within tissue sections or individual cells) using modified nucleotides that are coupled to a detectable marker, such as a fluorophore or an enzyme. This technique allows for the direct visualization and quantification of apoptotic cells within complex tissues or cell populations.

Antineoplastic combined chemotherapy protocols refer to a treatment plan for cancer that involves the use of more than one antineoplastic (chemotherapy) drug given in a specific sequence and schedule. The combination of drugs is used because they may work better together to destroy cancer cells compared to using a single agent alone. This approach can also help to reduce the likelihood of cancer cells becoming resistant to the treatment.

The choice of drugs, dose, duration, and frequency are determined by various factors such as the type and stage of cancer, patient's overall health, and potential side effects. Combination chemotherapy protocols can be used in various settings, including as a primary treatment, adjuvant therapy (given after surgery or radiation to kill any remaining cancer cells), neoadjuvant therapy (given before surgery or radiation to shrink the tumor), or palliative care (to alleviate symptoms and prolong survival).

It is important to note that while combined chemotherapy protocols can be effective in treating certain types of cancer, they can also cause significant side effects, including nausea, vomiting, hair loss, fatigue, and an increased risk of infection. Therefore, patients undergoing such treatment should be closely monitored and managed by a healthcare team experienced in administering chemotherapy.

Medical Definition of "Multiprotein Complexes" :

Multiprotein complexes are large molecular assemblies composed of two or more proteins that interact with each other to carry out specific cellular functions. These complexes can range from relatively simple dimers or trimers to massive structures containing hundreds of individual protein subunits. They are formed through a process known as protein-protein interaction, which is mediated by specialized regions on the protein surface called domains or motifs.

Multiprotein complexes play critical roles in many cellular processes, including signal transduction, gene regulation, DNA replication and repair, protein folding and degradation, and intracellular transport. The formation of these complexes is often dynamic and regulated in response to various stimuli, allowing for precise control of their function.

Disruption of multiprotein complexes can lead to a variety of diseases, including cancer, neurodegenerative disorders, and infectious diseases. Therefore, understanding the structure, composition, and regulation of these complexes is an important area of research in molecular biology and medicine.

A xenograft model antitumor assay is a type of preclinical cancer research study that involves transplanting human tumor cells or tissues into an immunodeficient mouse. This model allows researchers to study the effects of various treatments, such as drugs or immune therapies, on human tumors in a living organism.

In this assay, human tumor cells or tissues are implanted into the mouse, typically under the skin or in another organ, where they grow and form a tumor. Once the tumor has established, the mouse is treated with the experimental therapy, and the tumor's growth is monitored over time. The response of the tumor to the treatment is then assessed by measuring changes in tumor size or weight, as well as other parameters such as survival rate and metastasis.

Xenograft model antitumor assays are useful for evaluating the efficacy and safety of new cancer therapies before they are tested in human clinical trials. They provide valuable information on how the tumors respond to treatment, drug pharmacokinetics, and toxicity, which can help researchers optimize dosing regimens and identify potential side effects. However, it is important to note that xenograft models have limitations, such as differences in tumor biology between mice and humans, and may not always predict how well a therapy will work in human patients.

Embryonic development is the series of growth and developmental stages that occur during the formation and early growth of the embryo. In humans, this stage begins at fertilization (when the sperm and egg cell combine) and continues until the end of the 8th week of pregnancy. During this time, the fertilized egg (now called a zygote) divides and forms a blastocyst, which then implants into the uterus. The cells in the blastocyst begin to differentiate and form the three germ layers: the ectoderm, mesoderm, and endoderm. These germ layers will eventually give rise to all of the different tissues and organs in the body.

Embryonic development is a complex and highly regulated process that involves the coordinated interaction of genetic and environmental factors. It is characterized by rapid cell division, migration, and differentiation, as well as programmed cell death (apoptosis) and tissue remodeling. Abnormalities in embryonic development can lead to birth defects or other developmental disorders.

It's important to note that the term "embryo" is used to describe the developing organism from fertilization until the end of the 8th week of pregnancy in humans, after which it is called a fetus.

'Drosophila melanogaster' is the scientific name for a species of fruit fly that is commonly used as a model organism in various fields of biological research, including genetics, developmental biology, and evolutionary biology. Its small size, short generation time, large number of offspring, and ease of cultivation make it an ideal subject for laboratory studies. The fruit fly's genome has been fully sequenced, and many of its genes have counterparts in the human genome, which facilitates the understanding of genetic mechanisms and their role in human health and disease.

Here is a brief medical definition:

Drosophila melanogaster (droh-suh-fih-luh meh-lon-guh-ster): A species of fruit fly used extensively as a model organism in genetic, developmental, and evolutionary research. Its genome has been sequenced, revealing many genes with human counterparts, making it valuable for understanding genetic mechanisms and their role in human health and disease.

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... of cells in the major phases of the cell cycle. Cell cycle anomalies revealed on the DNA content frequency histogram are often ... Multiparameter analysis of the cell cycle includes, in addition to measurement of cellular DNA content, other cell cycle ... identifies the cell cycle phase position in the major phases (G0/G1 versus S versus G2/M phase) of the cell cycle. The cellular ... and G1B cell cycle compartments and also makes it possible to discriminate between S, G2 and mitotic cells. The cells in G1Q ...
After the cell has split into its two daughter cells, the cell enters G1. DNA repair processes and cell cycle checkpoints have ... known as the cell cycle control system, which monitors and dictates the progression of the cell through the cell cycle. This ... known as the cell cycle, a cell duplicates its contents and then divides in two. The purpose of the cell cycle is to accurately ... Cell cycle checkpoints are control mechanisms in the eukaryotic cell cycle which ensure its proper progression. Each checkpoint ...
The cell cycle uses these CDKs and CKIs to regulate the cell cycle through checkpoints. These checkpoints ensure that the cell ... The process by which the cell re-enters the cell cycle and dies is called "abortive cell cycle re-entry" and is characterized ... The Neuronal cell cycle represents the life cycle of the biological cell, its creation, reproduction and eventual death. The ... Cell cycle re-entry usually causes apoptosis. However, in some neurodegenerative diseases, re-entry into the cell cycle occurs ...
Not all cells carry out cell cycle withdrawal. In some cells, such as germ cells, stem cells and white blood cells, the ... Cell cycle withdrawal refers to the natural stoppage of cell cycle during cell division. When cells divide, there are many ... Temporary cell cycle withdrawal, also known as cell cycle arrest, refers to the short-term stoppage in cell division. This ... This prevents cells from cell dividing, withdrawing cells from the cell division cycle. Therefore, telomeres act as the buffer ...
... rescuing cell cycle progression by introducing another chemical) all the cells resume cell cycle progression at the same time. ... Jenkins CW, Xiong Y (1996). "Immunoprecipitation and Immunoblotting in Cell Cycle Studies". Cell Cycle - Materials and Methods ... In human somatic cells, the cell cycle lasts about 18 hours, and the G1 phase makes up about 1/3 of that time. On the other ... Induced cell cycle arrest is the use of a chemical or genetic manipulation to artificially halt progression through the cell ...
The reproductive-cell cycle theory posits that the hormones that regulate reproduction act in an antagonistic pleiotrophic ... Recent parabiosis studies prove many of the tenets of the Reproductive Cell-Cycle Theory of Aging. In these experiments, where ... Endocrinology of reproduction Bowen RL, Atwood CS (2011). "The reproductive-cell cycle theory of aging: an update". ... Since the most important change in an organism through time is the chemical reactions that result in a single cell developing ...
The swarmer cell has a single flagellum and polar pili and is characterized by its mobility, while the stacked cell has a stalk ... The stacked cell enters immediately in S-phase, while the swarmer cell stays in G1-phase and will differentiate to a stacked ... CcrM miss regulation have shown to produce severe miss control of cell cycle regulation and differentiation in various ... Woodcock, Clayton B.; Yakubov, Aziz B.; Reich, Norbert O. (August 2017). "Caulobacter crescentus Cell Cycle-Regulated DNA ...
A power cycle based on gasification of solid fuel and SOFCs is called an Integrated Gasification Fuel Cell (IGFC) cycle; the ... Lower-temperature fuel cell types such as the proton exchange membrane fuel cell, phosphoric acid fuel cell, and alkaline fuel ... Solid Oxide Fuel Cell Integrated Gasification Combined Cycle Giddey, S.; Badwal, S.P.S.; Kulkarni, A.; Munnings, C. (June 2012 ... This opens up the possibility of efficient fuel cell-based power cycles consuming solid fuels such as coal and biomass, the ...
In different assays and cell types, overexpression of this protein has been shown to activate or suppress cell cycle ... Regulator of cell cycle RGCC (RGCC) also known as response gene to complement 32 protein (RGC-32) is a protein that in humans ... This gene is thought to regulate cell cycle progression. It is induced by p53 in response to DNA damage, or by sublytic levels ... "The role of c5b-9 terminal complement complex in activation of the cell cycle and transcription". Immunol. Res. 31 (1): 37-46. ...
They found that when the cells were released and concurrently treated with nocodazole, a G2/M phase cell cycle inhibitor, ... Although telomerase activation does not occur during the cell cycle of normal somatic human cells, the association between ... In comparison, when cells were released and allowed to cycle, telomere length increased linearly with time. These data suggest ... These DSBs activate a DNA damage response pathway that halts the cell cycle until the breaks are repaired. This checkpoint ...
Ozawa S, Sugiyama Y, Mitsuhashi Y, Kobayashi T, Inaba M (1988). "Cell killing action of cell cycle phase-non-specific antitumor ... Alberts DS, Golde DW (November 1974). "DNA synthesis in multiple myeloma cells following cell cycle-nonspecific chemotherapy". ... Cell-cycle nonspecific antineoplastic agents (CCNS) refer to a class of pharmaceuticals that act as antitumor agents at all or ... any phases of the cell cycle. Alkylating antineoplastic agent and anthracyclins are two examples. "Chemotherapy: The Basics". ...
The intracellular accumulation of highly phosphorylated tau is linked to the cell cycle and cell cycle dependent kinases ( ... the cell-cycle hypothesis of Alzheimer's disease considers AD as a disease of deregulation of the cell cycle in neurons.[ ... research has shown that neuronal cell cycle reentry plays a fundamental role in the pathogenesis of AD. The cell cycle ... Since the cell is unable to complete the cell cycle, it dies via apoptosis (Meikrantz et al., 1995). In the past decade, ...
Cdc25 Cell biology Cell cycle Cell cycle checkpoint Cell cycle mathematical model Mitosis Spindle checkpoint Morgan D. (2006), ... Cells alive Cell Cycle and Cytokinesis - The Virtual Library of Biochemistry, Molecular Biology and Cell Biology Cell Cycle ... Portal CCO The Cell-Cycle Ontology Science Creative Quarterly's overview of the cell cycle (Cell cycle regulators, Cellular ... In this switch in mammalian cells, there are two cell cycle kinases that help to control the checkpoint: cell cycle kinases ...
... is an enzyme that in humans is encoded by the CDC7 gene. The Cdc7 kinase is ... "Entrez Gene: CDC7 cell division cycle 7 homolog (S. cerevisiae)". Kim JM, Yamada M, Masai H (November 2003). "Functions of ... Kumagai H, Sato N, Yamada M, Mahony D, Seghezzi W, Lees E, Arai K, Masai H (July 1999). "A novel growth- and cell cycle- ... Kumagai H, Sato N, Yamada M, Mahony D, Seghezzi W, Lees E, Arai K, Masai H (1999). "A novel growth- and cell cycle-regulated ...
"SON Controls Cell-Cycle Progression by Coordinated Regulation of RNA Splicing". Molecular Cell. 42 (2): 185-198. doi:10.1016/j. ... "Son Is Essential for Nuclear Speckle Organization and Cell Cycle Progression". Molecular Biology of the Cell. 21 (4): 650-663. ... SON-dependent cell-cycle genes possess a weak 5' or 3' splice site and are dependent on SON to ensure efficient splicing and ... The SON gene is required for RNA splicing of transcripts encoding the cell-cycle protein TUBG1 and genes maintaining hESC ...
... is a protein that slows cell division by slowing the progression of the cell cycle from the G1 phase to the S phase, thereby ... p16 is an inhibitor of cyclin-dependent kinases (CDK). It slows down the cell cycle by prohibiting progression from G1 phase to ... Ivanchuk SM, Mondal S, Rutka JT (June 2008). "p14ARF interacts with DAXX: effects on HDM2 and p53". Cell Cycle. 7 (12): 1836- ... Serrano M, Hannon GJ, Beach D (December 1993). "A new regulatory motif in cell-cycle control causing specific inhibition of ...
Cell Cycle. 8 (24): 4127-4137. doi:10.4161/cc.8.24.10240. PMID 19946211. Song, Byeongwoon; Young, C. S. H. (April 1998). " ... and immunity in various cells, but specifically hepatocytes, adipocytes, and hematopoietic cells. For example, in adipocytes, ... And furthermore, in cells lacking C/EBP or in C/EBP-deficient mice, both are unable to undergo adipogenesis. This results in ... It is frequently absent from genes that encode proteins used in virtually all cells. This box along with the GC box is known ...
Cell Cycle. 8 (17): 2756-68. doi:10.4161/cc.8.17.9387. PMID 19652553. Bianchi N, Zuccato C, Lampronti I, Borgatti M, Gambari R ... "MicroRNA-210 regulates mitochondrial free radical response to hypoxia and krebs cycle in cancer cells by targeting iron sulfur ... Cell. 35 (6): 856-67. doi:10.1016/j.molcel.2009.09.006. PMC 2782615. PMID 19782034. Chan SY, Zhang YY, Hemann C, Mahoney CE, ... Cell Metab. 10 (4): 273-84. doi:10.1016/j.cmet.2009.08.015. PMC 2759401. PMID 19808020. Bostjancic E, Zidar N, Glavac D (2009 ...
Peter ME (2009). "Let-7 and miR-200 microRNAs: guardians against pluripotency and cancer progression". Cell Cycle. 8 (6): 843- ... 4T1 cells) but not in other cells which are unable to colonize (4TO7 cells). Overexpression of miR-200c in non-metastatic 4TO7 ... In a series of mouse mammary isogenic cancer cell lines, the miR-200 family is highly expressed only in the cells that are able ... While the mir-200 family is highly expressed in normal epithelial cells, it is not expressed in normal fibroblast cells that ...
Macy B, Wang M, Yu HG (2009). "The many faces of shugoshin, the "guardian spirit," in chromosome segregation". Cell Cycle. 8 (1 ... It senses tension between sister chromatids during mitosis, and it degrades when they separate preventing cell cycle arrest and ... Cell Cycle. 5 (10): 1094-101. doi:10.4161/cc.5.10.2747. PMID 16687935. Salic A, Waters JC, Mitchison TJ (2004). "Vertebrate ... doi:10.1016/j.cell.2004.08.016. PMID 15339662. S2CID 14339817. Xu Z, Cetin B, Anger M, Cho US, Helmhart W, Nasmyth K, et al. ( ...
January 2006). "R-Spondin proteins: a novel link to beta-catenin activation". Cell Cycle. 5 (1): 23-6. doi:10.4161/cc.5.1.2305 ... Developmental Cell. 7 (4): 525-34. doi:10.1016/j.devcel.2004.07.019. PMID 15469841. Jin YR, Turcotte TJ, Crocker AL, Han XH, ...
Cell Cycle. 16 (14): 1345-1349. doi:10.1080/15384101.2017.1334022. PMC 5539816. PMID 28657421. Barranco Quintana, JL; Allam, MF ... It is currently unclear why brain volume decreases with age, however, a few causes may include: cell death, decreased cell ... Treatments with anticancer chemotherapeutic agents often are toxic to the cells of the brain, leading to memory loss and ...
September 2008). "Metformin slows down aging and extends life span of female SHR mice". Cell Cycle. 7 (17): 2769-2773. doi: ... "Old human cells rejuvenated with stem cell technology". News Center (in Samoan). Retrieved 26 July 2021. Ocampo A, Reddy P, ... A study shows that blood cells' loss of the Y chromosome in a subset of cells with age, reportedly affecting at least 40% of 70 ... A previously unknown cell mechanism involved in aging is discovered, which explains how cells 'remember' their identity when ...
Cell Cycle. 14 (14): 2226-2250. doi:10.1080/15384101.2015.1053672. PMC 4615001. PMID 26030272. Robles P, Quesada V (December ... Cell Cycle. 14 (14): 2226-2250. doi:10.1080/15384101.2015.1053672. PMC 4615001. PMID 26030272. Robles P, Quesada V (December ... Cell Systems. 2 (2): 101-111. doi:10.1016/j.cels.2016.01.013. PMID 27135164. Hamers L (2016). "Why do our cell's power plants ... Encyclopedia of Cell Biology. Waltham: Academic Press. pp. 545-554. doi:10.1016/b978-0-12-394447-4.10066-5. ISBN 978-0-12- ...
"MicroRNA-221-222 regulate the cell cycle in mast cells". Journal of Immunology. 182 (1): 433-445. doi:10.4049/jimmunol.182.1. ... Sun T, Yang M, Kantoff P, Lee GS (2009). "Role of microRNA-221/-222 in cancer development and progression". Cell Cycle. 8 (15 ... It targets CD117, which then prevents cell migration and proliferation in endothelial cells. miR-221 is known as an anti ... and MEK/ERK-mediated cell cycle regulation". Biol Chem. 391 (7): 791-801. doi:10.1515/BC.2010.072. PMID 20624000. S2CID ...
Cell Cycle. 8 (21): 3469-73. doi:10.4161/cc.8.21.9837. PMC 3593963. PMID 19829088. Zeng L, Carter AD, Childs SJ (Oct 2009). " ... and KLF4 and represses pluripotency in human embryonic stem cells". Cell. 137 (4): 647-58. doi:10.1016/j.cell.2009.02.038. PMID ... Chivukula RR, Mendell JT (May 2009). "Abate and switch: miR-145 in stem cell differentiation". Cell. 137 (4): 606-8. doi: ... independent cell death in urothelial cancer cell lines with targeting of an expression signature present in Ta bladder tumors ...
Cell Cycle. 5 (13): 1407-10. doi:10.4161/cc.5.13.2924. PMID 16855396. Gururaj AE, Peng S, Vadlamudi RK, Kumar R (2007). " ... BCAS3 is a gene that is amplified and overexpressed in breast cancer cells. The BCAS3 gene is regulated by estrogen receptor ...
Cell Cycle. 6 (6): 643-6. doi:10.4161/cc.6.6.4033. PMID 17374991. Shi Y, Zou M, Farid NR, Paterson MC (December 2000). " ... Cell. 84 (4): 587-97. doi:10.1016/S0092-8674(00)81034-X. PMID 8598045. S2CID 18792069. Pekarsky Y, Campiglio M, Siprashvili Z, ...
Controlling the Cell Cycle The cell cycle & Cell death Transcriptional program of the cell cycle: high-resolution timing Cell ... Cell cycle checkpoints are used by the cell to monitor and regulate the progress of the cell cycle. Checkpoints prevent cell ... This cyclin-Cdk driven cell cycle transitional mechanism governs a cell committed to the cell cycle that allows cell ... Using GFP to visualize the cell-cycle Science Creative Quarterlys overview of the cell cycle KEGG - Human Cell Cycle Archived ...
... the ordered sequence of events that occur in a cell in preparation for cell division. The cell cycle is a four-stage process in ... which the cell increases in size, copies its DNA, prepares to divide, and divides. Learn more about the cell cycle and the ... cell cycle, the ordered sequence of events that occur in a cell in preparation for cell division. The cell cycle is a four- ... Roger Williams University Open Publishing - The Cell Cycle and Mitosis. *The University of Hawaiʻi Pressbooks - The Cell Cycle ...
Due to their affiliation with DNA, histones are important for successful cell replication, which takes place via the cell cycle ... which takes place via the cell cycle.. Cell Cycle Timing. The cell cycle consists of four phases (G1, S, G2 and M), all of ... the post-translational changes occur throughout the cell cycle.. The most typical kind of cell cycle phosphorylation is on H3s ... Histones and the Cell Cycle. News-Medical. https://www.news-medical.net/life-sciences/Histones-and-the-Cell-Cycle.aspx. ( ...
... and genetics of cell cycle control in stalked C. crescentus cell. It reproduces protein time courses in wild-type cells, mimics ... Progression of a cell through the division cycle is tightly controlled at different steps to ensure the integrity of genome ... cell*Vsb*mass*k2. Vsb = 7.16092423585105; k2=2.0. => Cdh1; Cdc20A. cell*(kah1p+kah1pp*Cdc20A)*(1-Cdh1)/((Jah1+1)-Cdh1). kah1p ... A Data-Driven, Mathematical Model of Mammalian Cell Cycle Regulation. Michael C. Weis, Jayant Avva, James W. Jacobberger, Sree ...
The stress-activated kinase p38γ has a role in regulating entry into the cell cycle; in the liver, it can induce cellular ... regulating entry into the cell cycle. p38γ shares high sequence homology, inhibition sensitivity and substrate specificity with ... The cell cycle is a tightly regulated process that is controlled by the conserved cyclin-dependent kinase (CDK)-cyclin protein ... Tomás-Loba, A., Manieri, E., González-Terán, B. et al. p38γ is essential for cell cycle progression and liver tumorigenesis. ...
Quantification of cell-cycle state at a single-cell level is essential to understand fundamental three-dimensional (3D) ... We applied our workflow to quantify cell-cycle effects of three antimitotic cancer drugs over 8 d in HT-1080 fibrosarcoma ... Here, we present an integrated workflow for quantitative in vivo cell-cycle profiling. It combines image analysis and machine ... learning methods for automated 3D segmentation and cell-cycle state identification of individual cell-nuclei with widely ...
Loss of cell division cycle‑associated 5 promotes cell apoptosis by activating DNA damage response in clear cell renal cell ... Loss of cell division cycle‑associated 5 promotes cell apoptosis by activating DNA damage response in clear cell renal cell ... Silencing oncogene cell division cycle associated 5 induces apoptosis and G1 phase arrest of non-small cell lung cancer cells ... Silencing oncogene cell division cycle associated 5 induces apoptosis and G1 phase arrest of non-small cell lung cancer cells ...
The Gene Ontology (GO) project is a collaborative effort to address the need for consistent descriptions of gene products across databases. You can use this browser to view terms, definitions, and term relationships in a hierarchical display. Links to summary annotated gene data at MGI are provided in Term Detail reports.
The cellular cycle of eukaryotic cells consists of four phases: G1 phase, S phase, G2 phase and M phase. Cells increase in size ... The passage of a cell through the cell cycle is controlled by various cytoplasmic proteins in order to assure quality control. ... Mitosis is the briefest phase of the cell cycle, however is extremely important. During this period, nuclear and cytoplasmic ... When cells are not actively dividing they are considered to be in a state of quiescence, known as the G0 phase. ...
The presence of cell cycle markers in every one of the 10 MCI cases studied signifies a role for a cell cycle-driven process, ... Neuronal cell death is preceded by cell cycle events at all stages of Alzheimers disease. J Neurosci. 2003 Apr 1;23(7):2557-63 ... What happens when the protein machinery that drives the cell division cycle gets activated in non-dividing cells such as ... S and G2 phases of the cell cycle, respectively. The authors found a similar pattern in cells outside the hippocampus, such as ...
... such as those that regulate the eukaryotic cell division cycle. We describe here one modeling approach based on expressing the ... mathematical modeling can provide a powerful approach for investigating complex cell signaling networks, ... Mathematical modeling as a tool for investigating cell cycle control networks Methods. 2007 Feb;41(2):238-47. doi: 10.1016/j. ... We illustrate this approach throughout with the simple and well-characterized example of mitotic cell cycles in frog egg ...
... Authors Attila Csikász-Nagy. , Adrien Faure. , Roberto ... In the mammalian system the transcription of the cell cycle regulatory protein Wee1 is controlled by the circadian clock. ... Biological data points to additional couplings, including a link back from the cell cycle to the circadian clock. Proper ... 2007) present a computational model coupling the cell cycle and circadian rhythm, showing that this coupling can lead to ...
Automatically cite a film/online video in CELL-CYCLE by using Citation Machines free citation generator. ... Creating accurate citations in CELL-CYCLE has never been easier! ...
Analytica-world.com offer you a news overview of current science and industry news for cell cycle ... Big Data for small cells - a new tracking and quantification tool for single cells 20-Jul-2016 - Working with colleagues from ... how the genetic material is compacted and de-compacted in a timely fashion during the different phases of the cell cycle. "We ... the enzyme that cuts the amino acid tyrosine off an important part of the cells skeleton. Researchers of the Netherlands ...
... including those that are regulated during the cell cycle. However, recent evidence indicates that Sp1 belongs to a larger ... Sp1 trans-activation of cell cycle regulated promoters is selectively repressed by Sp3 Biochemistry. 1995 Dec 19;34(50):16503-8 ... including those that are regulated during the cell cycle. However, recent evidence indicates that Sp1 belongs to a larger ... Using antibodies specific for Sp1 and Sp3, we observe that both of these factors localize to the cell nucleus and have a ...
Misregulation of the cell cycle may result in malignant cell proliferation, tumorigenesis or cell death. In this chapter, we ... duplication cycle and the DNA replication cycle in a cell are coordinated tightly to occur once and only once per cell cycle. ... The connections between DNA replication and other cell cycle events. DNA replication occurs once and only once per cell cycle ... The cell cycle is the process of accurate self-reproduction and proliferation of a cell. It is the basis of the growth, ...
Cell Cycle Life Science Poster. Our Cell Cycle & DNA Damage Repair poster summarizes the stages of the cell cycle and DNA ... Cell Cycle and DNA Damage product guide. Our Cell Cycle and DNA Damage Research Guide highlights over 750 products for cell ... Cell Cycle & DNA Damage Repair Poster. In normal cells, each stage of the cell cycle is tightly regulated, however in cancer ... Cell Cycle and DNA Damage Research Product Guide. This product guide provides a review of the cell cycle and DNA damage ...
Our research is focused on applying discoveries from cell cycle regulation and genome instability to modern cancer therapeutics ...
To consistently produce healthy cells, the cell cycle-the process that generates daughter cells-must be precisely regulated. ... "Immunomodulatory Roles of Cell Cycle Regulators." Frontiers in Cell and Developmental Biology 7 (2019). [Source] ... At these checkpoints, positive and negative regulators promote or inhibit a cells continuation through the cell cycle. ... To regulate the cell cycle, cyclins must be bound to a Cyclin-dependent kinase (CDK)-a type of enzyme that attaches a phosphate ...
During cell growth and proliferation, ubiquitin plays an outsized role in promoting progression through the cell cycle. In ... Notably, the G1/S boundary represents a major barrier to cell proliferation and is universally dysfunctional in cancer cells, ... degradation is critically important at transition points where it provides directionality and irreversibility to the cell cycle ... and the potential role of these pathways in the cancer cycle and disease proliferation. ...
... reviewing the state of the Plasmodium cell cycle field. (Checks and Balances? DNA replication and the cell cycle in Plasmodium ... Remarkably little is known about Plasmodium cell cycles, despite a wealth of knowledge on the subject in human cells. This ... the replication mode used by most cells from human cells to yeast cells. In schizogony a single parasite first generates many ... Aim 4: investigate cell-cycle checkpoints and replicative responses to the changing environment in the human host and to ...
... and immune cell infiltration levels. Finally, the interaction between HNK and two HNK-targets regulating the cell cycle was ... such as inducing cell cycle arrest, inhibiting metastasis, and overcoming immunotherapy resistance in breast cancer cells. ... However, the molecular mechanisms of action of HNK in BCSCs, as well as its effects on the cell cycle, remain unclear. This ... BCSCs are mostly dormant, and therefore, activating them and modulating the cell cycle are important for successful therapy ...
... on Phases of the Cell Cycle in the context of Mitosis and Cell Division to help students study for a college level Cell Biology ... Phases of the Cell Cycle. The cell cycle is a series of carefully regulated events, including periods of growth, rest, and cell ... The cell cycle consists of four distinct phases: the G1 phase, the first phase of the cell cycle, when a cell grows; the S ... The cell plate fuses with the cell membrane to form two daughter cells. A new cell wall forms between the membranes of the cell ...
Organizers: IRB BarcelonaDate: Friday 5th April, 12.00hPlace: AUDITORIUM, Parc Cientific de Barcelona Host: Xavier Salvatella, Ph.D., IRB Barcelona Plenary Seminar
... leads to cell cycle arrest and apoptosis ,i,in vitro,/i, in keratinocytes, the target cells in psoriasis. Tan IIA inhibited ... single-cell gel electrophoresis assay (SCGE), and flow cytometry methods. Apoptosis was partially blocked by the caspase-3 ... Analysis of Cell Cycle Alterations Induced by Tan IIA. The inhibition of growth in Tan IIA-treated cells may result from cell ... The cell cycle was modeled and data were expressed as a percentage of apoptotic cells in the total cell preparation. All data ...
DNA endoreduplication initiation involved in cell cycle DNA replication; DNA re-replication initiation involved in cell cycle ... DNA replication initiation involved in cell cycle DNA replication; DNA-dependent DNA replication initiation involved in cell ... Any DNA replication initiation that is involved in cell cycle DNA replication. ... Genes QTLs Strains Markers Genome Information Ontologies Cell Lines References Download Submit Data ...
Click on grid cells to view annotations.. *Blue cells = expressed in wild-type.. Gray triangles = other expression annotations ... J:142754 Hansen GM, et al., Large-scale gene trapping in C57BL/6N mouse embryonic stem cells. Genome Res. 2008 Oct;18(10):1670- ...
To investigate the effect of icariin on cell cycle and apoptosis of medulloblastoma cells and its mechanism. Medulloblastoma ... Icariin Regulates Cell Cycle Related Proteins and Apoptosis Related Proteins and Affects Cell Cycle and Apoptosis of ... To investigate the effect of icariin on cell cycle and apoptosis of medulloblastoma cells and its mechanism. Medulloblastoma ... and induce cell apoptosis by regulating the expression of B-cell lymphoma 2, cleaved caspase-3, cleaved caspase-9 and cleaved ...
speedy/RINGO cell cycle regulator family member A. acts_upstream_of_or_within. ISO. MGI:5888863 (MGI:5829137,PMID:28031483). ... chromosome organization involved in meiotic cell cycle. go back to main search page ... chromosome organization involved in meiotic cell cycle. 73. centromere detachment from spindle pole body involved in meiotic ... chromosome organization involved in meiotic cell cycle. 73. centromere detachment from spindle pole body involved in meiotic ...
Le stockage ou laccès technique qui est utilisé exclusivement à des fins statistiques. Le stockage ou laccès technique qui est utilisé exclusivement dans des finalités statistiques anonymes. En labsence dune assignation à comparaître, dune conformité volontaire de la part de votre fournisseur daccès à internet ou denregistrements supplémentaires provenant dune tierce partie, les informations stockées ou extraites à cette seule fin ne peuvent généralement pas être utilisées pour vous identifier. ...
  • To ensure the proper replication of cellular components and division, there are control mechanisms known as cell cycle checkpoints after each of the key steps of the cycle that determine if the cell can progress to the next phase. (wikipedia.org)
  • If DNA damage or abnormalities in spindle formation are detected at these checkpoints, the cell is forced to undergo programmed cell death, or apoptosis . (britannica.com)
  • For a cell to progress through the cycle and replicate, it must pass through checkpoints between phases to ensure that DNA is replicated correctly and that chromosomes segregate. (tocris.com)
  • These checkpoints may stop the cell cycle after DNA damage, loss of DNA replication or disruption of the mitotic spindle, in order for repair processes to take place. (tocris.com)
  • Internal regulatory checkpoints ensure that a cell's size, energy reserves, and DNA quality and completeness are sufficient to advance through the cell cycle. (jove.com)
  • At these checkpoints, positive and negative regulators promote or inhibit a cell's continuation through the cell cycle. (jove.com)
  • Positive regulators include two protein groups that allow cells to pass through regulatory checkpoints: cyclins and cyclin-dependent kinases (CDKs). (jove.com)
  • d) investigation of cell-cycle checkpoints and replicative responses to the changing environment in the human host and to antimalarial drugs. (europa.eu)
  • Cell proliferation includes a series of events that is tightly regulated by several checkpoints and layers of control mechanisms. (frontiersin.org)
  • Many more investigations have been made on cells, sorted according to size, or artificially arrested at various cell cycle checkpoints. (frontiersin.org)
  • Further, I show that during a wild-type cell cycle, checkpoints are responsible for arresting the bulk of periodic transcription. (duke.edu)
  • G1 Phase Cell Cycle Checkpoints" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (umassmed.edu)
  • This graph shows the total number of publications written about "G1 Phase Cell Cycle Checkpoints" by people in this website by year, and whether "G1 Phase Cell Cycle Checkpoints" was a major or minor topic of these publications. (umassmed.edu)
  • Below are the most recent publications written about "G1 Phase Cell Cycle Checkpoints" by people in Profiles. (umassmed.edu)
  • it is often a biochemical alternative to the self-destruction of such a damaged cell by apoptosis. (wikipedia.org)
  • For example, mutations in a protein called p53 , which normally detects abnormalities in DNA at the G1 checkpoint, can enable cancer-causing mutations to bypass this checkpoint and allow the cell to escape apoptosis. (britannica.com)
  • Loss of cell division cycle‑associated 5 promotes cell apoptosis by activating DNA damage response in clear cell renal cell carcinoma. (nih.gov)
  • Silencing oncogene cell division cycle associated 5 induces apoptosis and G1 phase arrest of non-small cell lung cancer cells via p53-p21 signaling pathway. (nih.gov)
  • Downregulation of CDCA5 Can Inhibit Cell Proliferation, Migration, and Invasion, and Induce Apoptosis of Prostate Cancer Cells. (nih.gov)
  • If cells containing damaged DNA were to divide, the errors would be transmitted to daughter cells, generating genomic instability and resulting in tumorigenesis or apoptosis . (tocris.com)
  • The aim of the present investigation was to elucidate the cellular mechanisms whereby Tanshinone IIA (Tan IIA) leads to cell cycle arrest and apoptosis in vitro in keratinocytes, the target cells in psoriasis. (hindawi.com)
  • Furthermore, Tan IIA-induced apoptosis and mitochondrial membrane potential changes were also further demonstrated by DNA fragmentation, single-cell gel electrophoresis assay (SCGE), and flow cytometry methods. (hindawi.com)
  • Therefore, based on clinical experience as well as cytotoxic activity against multiple human cancer cells, we hypothesized that induction of apoptosis is the underlying mechanism for the treatment of psoriasis. (hindawi.com)
  • To investigate the effect of icariin on cell cycle and apoptosis of medulloblastoma cells and its mechanism. (ijpsonline.com)
  • Icariin can inhibit the proliferation and colony forming ability of medulloblastoma cells, induce cell arrest in synthesis phase by inhibiting the expression of cyclin A, cyclin-dependent kinase 2 and cyclin B1, and induce cell apoptosis by regulating the expression of B-cell lymphoma 2, cleaved caspase-3, cleaved caspase-9 and cleaved poly (ADP-ribose) polymerase protein. (ijpsonline.com)
  • Resveratrol could play a toxic role through inducing apoptosis of the cancer cell in a time- and concentration-dependent manner. (mdpi.com)
  • Wu X, Song M, Qiu P, Li F, Wang M, Zheng J, Wang Q, Xu F, Xiao H. A metabolite of nobiletin, 4'-demethylnobiletin and atorvastatin synergistically inhibits human colon cancer cell growth by inducing G0/G1 cell cycle arrest and apoptosis. (umassmed.edu)
  • Bufalin induces G0/G1 phase arrest through inhibiting the levels of cyclin D, cyclin E, CDK2 and CDK4, and triggers apoptosis via mitochondrial signaling pathway in T24 human bladder cancer cells. (umassmed.edu)
  • MicroRNAs ( miRNA ) are conserved, endogenous, short non- coding RNAs composed of 18-25 nucleotides that serve as potential markers for many diseases and are involved in various biological processes , including cell proliferation , apoptosis , and differentiation. (bvsalud.org)
  • The proteins that play a role in stimulating cell division can be classified into four groups- growth factors , growth factor receptors , signal transducers, and nuclear regulatory proteins ( transcription factors ). (britannica.com)
  • Cells use special proteins and checkpoint signaling systems to ensure that the cell cycle progresses properly. (britannica.com)
  • However, the cell cycle and its checkpoint systems can be sabotaged by defective proteins or genes that cause malignant transformation of the cell, which can lead to cancer . (britannica.com)
  • The mechanism, which is based on the synthesis and degradation of three ''master regulator'' proteins (CtrA, GcrA, and DnaA), is converted into a quantitative model, in order to study the temporal dynamics of these and other cell cycle proteins. (ebi.ac.uk)
  • Since many of the proteins involved in regulating the cell cycle of C. crescentus are conserved among many genera of a-proteobacteria, the proposed mechanism may be applicable to other species of importance in agriculture and medicine. (ebi.ac.uk)
  • The passage of a cell through the cell cycle is controlled by various cytoplasmic proteins in order to assure quality control. (novusbio.com)
  • Yang and colleagues used antibodies to test the presence of various cell cycle proteins in MCI, AD, and control brain samples taken at autopsy. (alzforum.org)
  • In the hippocampus, one of the first areas affected by the disease, both AD and MCI samples had robust staining for cyclin D1, DNA polymerase, and cyclin B1, proteins that are synthesized only during the G1, S and G2 phases of the cell cycle, respectively. (alzforum.org)
  • Recent breakthroughs have uncovered more and more DNA replication licensing machinery proteins (ORC, Cdc6, Cdt1, geminin, etc.) functioning in other cell cycle events, including centrosome replication, mitotic events, transcription and so on. (intechopen.com)
  • In normal cells, each stage of the cell cycle is tightly regulated, however in cancer cells many genes and proteins that are involved in the regulation of the cell cycle are mutated or over expressed. (tocris.com)
  • A cells cycle is positively regulated promoting progress through the stages via the interaction of two classes of proteins found in the cytoplasm. (jove.com)
  • Although live imaging has provided extensive insights into this relationship at the single-cell level, the limited number of fluorescent markers that can be used in a single experiment has hindered efforts to link the dynamics of individual proteins responsible for decision making directly to cell cycle progression. (cam.ac.uk)
  • In addition, to allow manipulating the levels of endogenous proteins at will, we introduce a novel approach to render already existing GFP (trap) lines amenable to auxin-dependent degradation by simple ectopic expression of a degradation cassette using human cells and zebrafish as a proofs of principle. (cam.ac.uk)
  • T he presence and activity of various proteins are required in the cell cycle progression. (ukessays.com)
  • We generated LCL-stimulated T cell lines from 21 donors according to clinical protocols, and analyzed the antigen specificity of the CD4+ component in EBV-specific T cell preparations using a genetically engineered EBV mutant that is unable to enter the lytic cycle, and recombinantly expressed and purified EBV proteins. (uni-muenchen.de)
  • Lytic cycle antigens were predominantly derived from structural proteins of the virus presented on MHC II via receptor-mediated uptake of released viral particles, but also included abundant infected cell proteins whose presentation involved intercellular protein transfer. (uni-muenchen.de)
  • Microbial proteins such as single-cell proteins (SCPs) have been introduced as feed alternatives since they can replace current fish feed ingredients, e.g., soybean, which are associated with negative environmental impacts. (lu.se)
  • Let-7 Let-7 has an essential role in cell cycle and the differentiation of cell cycle terminals. (ukessays.com)
  • Depletion of the cell-cycle inhibitor p27 ( Xic1 ) impairs neuronal differentiation and increases the number of ElrC (+) progenitor cells in Xenopus tropicalis. (xenbase.org)
  • To investigate whether p27(Xic1) is necessary for cell cycle exit and/or neuronal differentiation, we used antisense morpholino oligos (MO) to knockdown the protein levels in vivo. (xenbase.org)
  • At the same time, we found an increase in the expression of ElrC, a marker of cells as they undergo a transition from proliferation to differentiation. (xenbase.org)
  • miR-203 drives breast cancer cell differentiation. (medscape.com)
  • Its prominent properties are A lack of cell differentiation Local invasion of adjoining tissue Metastasis, which is spread to distant sites through. (msdmanuals.com)
  • In cells with nuclei (eukaryotes, i.e., animal, plant, fungal, and protist cells), the cell cycle is divided into two main stages: interphase and the mitotic (M) phase (including mitosis and cytokinesis). (wikipedia.org)
  • During interphase, the cell grows, accumulating nutrients needed for mitosis, and replicates its DNA and some of its organelles. (wikipedia.org)
  • The eukaryotic cell cycle consists of four distinct phases: G1 phase, S phase (synthesis), G2 phase (collectively known as interphase) and M phase (mitosis and cytokinesis). (wikipedia.org)
  • M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's nucleus divides, and cytokinesis, in which the cell's cytoplasm divides forming two daughter cells. (wikipedia.org)
  • Analysis of mitosis and antimitotic drug responses in tumors by in vivo microscopy and single-cell pharmacodynamics. (nature.com)
  • Mitosis is the briefest phase of the cell cycle, however is extremely important. (novusbio.com)
  • When B levels drop, the cell exits mitosis and divides. (jove.com)
  • A fifth phase has been identified, G0, in which the cell is resting just after mitosis but still carrying out normal functions. (coursehero.com)
  • The M phase consists of mitosis, in which the cell divides, producing two new, identical cells. (coursehero.com)
  • Interphase is collectively the gap 1 (G1), synthesis (S), and gap 2 (G2) phases of mitosis, in which a cell grows, replicates its DNA, and grows again. (coursehero.com)
  • Other cellular structures are duplicated during G2, such that each replicated daughter cell produced during mitosis will have all necessary organelles (such as mitochondria, endoplasmic reticulum, etc. (coursehero.com)
  • 1 Department of Cell Biology, University of Massachusetts Medical School, Worcester 01655, USA. (nih.gov)
  • Understanding the regulatory mechanisms that control cell-cycle events remains to be a fundamental question in cell biology. (duke.edu)
  • After being promoted to Senior Investigator, he moved to Singapore where he worked at the Institute of Molecular Cell Biology (IMCB/A*STAR/National University of Singapore). (lu.se)
  • During the mitotic phase, the replicated chromosomes, organelles, and cytoplasm separate into two new daughter cells. (wikipedia.org)
  • Some cells enter the G0 phase semi-permanently and are considered post-mitotic, e.g., some liver, kidney, and stomach cells. (wikipedia.org)
  • The word "post-mitotic" is sometimes used to refer to both quiescent and senescent cells. (wikipedia.org)
  • We illustrate this approach throughout with the simple and well-characterized example of mitotic cell cycles in frog egg extracts. (nih.gov)
  • It also highlights strategies for enhancing replicative stress in cancer cells to force mitotic catastrophe and cell death. (tocris.com)
  • We have previously shown that p27(Xic1) is expressed in the cells of the neural plate as they become post-mitotic (Development 127 (2000) 1303). (xenbase.org)
  • The cellular cycle of eukaryotic cells consists of four phases: G1 phase, S phase, G2 phase and M phase. (novusbio.com)
  • The transcription factor Sp1 plays a key role in the activation of many cellular and viral gene promoters, including those that are regulated during the cell cycle. (nih.gov)
  • In the present study, we analyze the activity and binding of Sp3 on several eukaryotic promoters that contain G/C boxes and are known to be regulated during cellular proliferation and the cell cycle. (nih.gov)
  • DNA DAMAGE, or the deficiencies in specific cellular components or nutrients may cause the cells to halt before progressing through G1 phase. (umassmed.edu)
  • Inter-cellular variability in the duration of the cell cycle is a well documented phenomena which has been integrated into mathematical models of cell proliferation since the 70's. (hamilton.ie)
  • Here I present a minimalist stochastic cell cycle model that allows for inter-cellular variability at the level of each single phase, i.e. (hamilton.ie)
  • To resolve this uncertainty a novel experimental proto col is proposed able to provide sufficient information about cell kinetics to fully determine both the inter-cellular average and variance of the duration of each of the phases. (hamilton.ie)
  • This is the multihit theory of tumorigenesis, in which a series of multiple triggering events in the genetic and cellular makeup of a cell ultimately cause cancer. (medscape.com)
  • Cell cycle kinetics are crucial to cell fate decisions. (cam.ac.uk)
  • Focusing on cyclin D1 as a major cell cycle regulator, we present evidence that a crucial cell cycle function of cyclin D1 is to prevent the transition into quiescence and identify a unique cyclin D1 protein kinetics that are indicative of very short G1 phases. (cam.ac.uk)
  • A re-evaluation of parameters of cell kinetics in view of our increasing knowledge of the molecular pathways of cell cycle control may provide more prognostic information for the management of patients with malignant lymphomas. (bmj.com)
  • Fitting this model to flow cytometry data from 5-bromo-2'-deoxyuridine (BrdU) pulse labeling experiments of two different cell lines shows that the mean field predictions mimic closely the measured average kinetics. (hamilton.ie)
  • Proliferation-linked shifts in eligibility of T-cell progenitors, population dynamics, DN1 cells to undergo specification thus control kinetics of T-cell generation. (lu.se)
  • A centromere , the point on a chromosome that attaches to the spindle fibers with a kinetochore during cell division, attaches the sister chromatids. (coursehero.com)
  • A process of chromosome organization that is involved in a meiotic cell cycle. (mcw.edu)
  • Moreover, the parS chromosomal context in non-replicative cells, combined with ParB depletion at cell division, critically contribute to the unique cell cycle-dependent organization of the centromere in this bacterium, highlighting new levels of complexity in chromosome segregation and cell cycle control. (jic.ac.uk)
  • But we probadly did not see the significant difference against 5000mAh competitors in first 1000 cycles. (endless-sphere.com)
  • I don't understand how you get 1000 cycles above 80% 100% dod for example for M36- not realistic. (endless-sphere.com)
  • 4.1v 0.3C - 0.5C discharge - around 80% at 1000 cycles. (endless-sphere.com)
  • Finally, transcription factors within the nucleus must initiate the transcription of genes involved in cell proliferation. (britannica.com)
  • The replication independent histone genes are transcribed at a relatively constant low rate, regardless of cell cycle stage. (news-medical.net)
  • However, most of the vertebrate histone genes are replication dependent and are therefore more highly expressed during the cell cycle's S phase. (news-medical.net)
  • Therefore, NPAT could be the link between cell cycle machinery and shared heightened transcription of histone genes during S phase. (news-medical.net)
  • The intersection between the differentially expressed genes (DEGs) and the HNK-targets was determined using a Venn diagram, and the results were analyzed using a protein-protein interaction network, hub gene selection, gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, genetic alteration analysis, survival rate, and immune cell infiltration levels. (hindawi.com)
  • Here, we used quantitative real-time PCR, profiling the expression of 93 genes in single-cells from three different cell lines. (frontiersin.org)
  • We found that the total transcript level per cell and the expression of most individual genes correlated with progression through the cell cycle, but not with cell size. (frontiersin.org)
  • Detailed analysis of cell cycle predictive genes allowed us to define subpopulations with distinct gene expression profiles and to calculate a cell cycle index that illustrates the transition of cells between cell cycle phases. (frontiersin.org)
  • In conclusion, we provide useful experimental approaches and bioinformatics to identify informative and predictive genes at the single-cell level, which opens up new means to describe and understand cell proliferation and subpopulation dynamics. (frontiersin.org)
  • Here, we employed single-cell gene expression profiling to describe the dynamic transition between cell proliferative states in three different cell lines using a panel consisting of 93 marker genes. (frontiersin.org)
  • When UV rays damage genes that control cell growth and division, cells can grow too fast and in an uncontrolled way. (medlineplus.gov)
  • These cycles are set by circadian clock genes that are found in nearly every cell in our bodies. (cdc.gov)
  • The N-terminal phosphorylation of RB by p38 bypasses its inactivation by CDKs and prevents proliferation in cancer cells. (nature.com)
  • Quantification of cell-cycle state at a single-cell level is essential to understand fundamental three-dimensional (3D) biological processes such as tissue development and cancer. (nature.com)
  • We applied our workflow to quantify cell-cycle effects of three antimitotic cancer drugs over 8 d in HT-1080 fibrosarcoma xenografts in living mice using a data set of 38,000 cells and compared the induced phenotypes. (nature.com)
  • Our research is focused on applying discoveries from cell cycle regulation and genome instability to modern cancer therapeutics. (uwo.ca)
  • Adapted from the 2015 Cancer Product Guide, Edition 3, this poster summarizes the stages of the cell cycle and DNA repair. (tocris.com)
  • Notably, the G1/S boundary represents a major barrier to cell proliferation and is universally dysfunctional in cancer cells, allowing for the unbridled proliferation observed in malignancy. (intechopen.com)
  • Numerous E3 ubiquitin ligases, which facilitate the ubiquitination of specific substrates, have been shown to control G1/S. In this chapter, we will discuss components in the ubiquitin proteasome system that are implicated in G1/S control, how these enzymes are interconnected, gaps in our current knowledge, and the potential role of these pathways in the cancer cycle and disease proliferation. (intechopen.com)
  • Breast cancer stem cells (BCSCs) play a critical role in chemoresistance, metastasis, and poor prognosis of breast cancer. (hindawi.com)
  • is known to exert anticancer effects, such as inducing cell cycle arrest, inhibiting metastasis, and overcoming immunotherapy resistance in breast cancer cells. (hindawi.com)
  • Chemoresistance, or the insensitivity of cancer cells to drug therapy, is a major factor in the failure of chemotherapy against breast cancer. (hindawi.com)
  • Breast cancer stem cells (BCSCs) are one of the main factors driving chemoresistance, thereby contributing to poor prognosis and clinical outcomes [ 3 - 5 ]. (hindawi.com)
  • In this study, by comparing the activity of normal cell lines and cancer cell lines after treating with resveratrol, it was found that resveratrol has more significant cytotoxicity in cancer cell lines. (mdpi.com)
  • 1) For example, the down-regulation of miR15s and miR - 16 - 1 in chronic lymphocytic leukaemia, prostate cancer and pituitary tumours, leading to the inhibition of tumour growth and induce cell cycle arrest at the G 1 - phase by target cell cycle regulators ( cyclin D1, cyclin E1, cyclin D3 and CDK6). (ukessays.com)
  • A Hepatocellular carcinoma in humans HepG2 cells are forced to undergo Oxidative Phosphorylation (OXPHOS) when grown in aglycemic conditions with galactose and glutamine.These OXPHOS cells serve as a prototype for cancer cells' combined aerobic glycolysis and OXPHOS bioenergetics. (pulsus.com)
  • It was our goal to identify the portions of the glutaminolytic pathway that involved the aminotransferase reaction that supplied 2-oxoglutarate (2OG) to the Krebs cycle active segment with Aconitase And Isocitrate Dehydrogenase-3 (ACO-IDH3), which is typically inactive in cancer cells because citrate is exported from the mitochondria. (pulsus.com)
  • Thus, under conditions frequently established for solid tumours in vivo, such as aglycemia and hypoxia, the metabolic flexibility of cancer cells is demonstrated. (pulsus.com)
  • In turn, as a result of research into the abnormal cancer cell, the basic understanding of the cell has greatly improved. (medscape.com)
  • Cancer is characterized by uncontrolled growth and division of a cell, with extension beyond the normally limiting basement membrane and through the boundaries of normal cells. (medscape.com)
  • [ 6 ] These events lead the cancer cell to escape normal cell growth and control mechanisms, to avoid system control mechanisms (ie, immunologic surveillance), and to establish a nutrient supply. (medscape.com)
  • High-risk types (e.g., types 16 and 18) can cause low-grade cervical cell abnormalities, high-grade cervical cell abnormalities that are precursors to cancer, and cancers ( 5 - 7 ). (cdc.gov)
  • L'étude menée en Iraq a utilisé la méthode d'hybridation in situ pour déterminer la fréquence du papillomavirus humain et pour son génotypage dans les échantillons de tissus prélevés auprès de 129 patientes ayant reçu un diagnostic de cancer du sein malin, de 24 patientes porteuses d'une tumeur du sein bénigne et de 20 femmes témoins en bonne santé. (who.int)
  • These results suggest a strong link between ovulatory menstrual cycles and the risk of developing breast cancer, with progesterone playing an important role. (medscape.com)
  • For example, in addition to promoting sleep, melatonin can also stop tumor growth and protect against the spread of cancer cells. (cdc.gov)
  • Many factors are involved in causing and permitting the unregulated proliferation of cells that occurs in cancer. (msdmanuals.com)
  • Overview of Cancer Cancer is an unregulated proliferation of cells. (msdmanuals.com)
  • Cancer cells, particularly those arising from the bone marrow or lymphatic system, may have a short generation time, and there usually are a smaller percentage of cells in G0 (resting phase). (msdmanuals.com)
  • A subpopulation of cells within a cancer has the properties of stem cells. (msdmanuals.com)
  • A cancer may release cells into the circulation at a very early stage of development. (msdmanuals.com)
  • Circulating cancer cells are present in many patients with advanced cancer and even in some with localized disease. (msdmanuals.com)
  • Although most circulating cancer cells die, an occasional cell may penetrate into tissues, generating a metastasis at a distant site. (msdmanuals.com)
  • Experiments suggest that the abilities to invade, migrate, and successfully implant and stimulate new blood vessel growth are all important properties of the cells that cause metastases, which are likely a subpopulation of the primary cancer. (msdmanuals.com)
  • Cancer cells often present neoantigens on their cell surface that can be detected as "non-self" by the immune system, resulting in an attack by the immune system. (msdmanuals.com)
  • After cell division, each of the daughter cells begin the interphase of a new cell cycle. (wikipedia.org)
  • Although the various stages of interphase are not usually morphologically distinguishable, each phase of the cell cycle has a distinct set of specialized biochemical processes that prepare the cell for initiation of the cell division. (wikipedia.org)
  • Interphase is a series of changes that takes place in a newly formed cell and its nucleus before it becomes capable of division again. (wikipedia.org)
  • Typically interphase lasts for at least 91% of the total time required for the cell cycle. (wikipedia.org)
  • The stages G1, S, and G2 make up interphase, which accounts for the span between cell divisions. (britannica.com)
  • The G1, S, and G2 phases of the cell cycle are collectively known as interphase. (coursehero.com)
  • A cell spends most of its time in interphase, during which it mostly performs its normal functions, such as protein synthesis. (coursehero.com)
  • Interphase is characterized by cell growth and DNA replication , while M is the phase of the cell cycle in which the chromosomes of the cell prepare for the cell to divide into two new cells. (coursehero.com)
  • Interphase comprises the gap 1 (G1), synthesis (S), and gap 2 (G2) phases, in which the cell grows and replicates its genetic material. (coursehero.com)
  • Interphase, the part of the cell cycle between division events, includes the G1, S, and G2 phases, during which the cell grows, replicates its DNA, and undergoes its usual functions. (coursehero.com)
  • Interphase takes most of the time in the cell cycle, comprising more than 95% of the duration of the cell cycle in most eukaryotes. (coursehero.com)
  • During interphase, a cell grows larger. (coursehero.com)
  • Misregulation of the cell cycle may result in malignant cell proliferation, tumorigenesis or cell death. (intechopen.com)
  • Breast metastatic tumors in lung can be substituted by lung-derived malignant cells transformed by alternative splicing H19 lncRNA. (medscape.com)
  • In this dissertation, I explore the mechanisms that coordinate and regulate cell-cycle progression in the budding yeast, Saccharomyces cerevisiae. (duke.edu)
  • Transforming growth factor (3(TGF-P) is a crucial mediator of mammary epithelial morphogenesis and can negatively regulate cell cycle progression. (uwo.ca)
  • DNA replication occurs once and only once per cell cycle mainly regulated by DNA replication initiation factors in eukaryotic cells. (intechopen.com)
  • However, the genome can also be copied extremely rapidly during the sexual cycle, which occurs in the malaria-transmitting mosquito. (europa.eu)
  • Aim 1: detailed characterisation, at the whole-cell level, of the asynchronous genome replication that occurs in schizogony and gametogenesis. (europa.eu)
  • Negative growth regulation generally occurs during the G0/G1 phase of the cell cycle, yet the redundancy and complexity among components of this regulatory network have made it difficult to discern how negative growth cues protect cells from aberrant proliferation. (uwo.ca)
  • DNA damage occurs frequently, but normal cells are usually able to fix it before it can cause problems. (medlineplus.gov)
  • The replication cycle of HIV occurs exclusively within infected cells, although HIV may also be found extracellularly when new progeny viruses are released from the cell by budding. (cdc.gov)
  • It reproduces protein time courses in wild-type cells, mimics correctly the phenotypes of many mutant strains, and predicts the phenotypes of currently uncharacterized mutants. (ebi.ac.uk)
  • The cell cycle is a tightly regulated process that is controlled by the conserved cyclin-dependent kinase (CDK)-cyclin protein complex 1 . (nature.com)
  • What happens when the protein machinery that drives the cell division cycle gets activated in non-dividing cells such as neurons? (alzforum.org)
  • In the mammalian system the transcription of the cell cycle regulatory protein Wee1 is controlled by the circadian clock. (dagstuhl.de)
  • The precise regulations of pre-RC protein levels and assembly are effective ways to prevent reassembly of de novo MCM2-7 onto the replicated origins to re-license and re-replicate the genomic DNA in the subsequent phases of the same cell cycle ( Figure 1) . (intechopen.com)
  • When this complex forms the CDK can phosphorylate a target protein which alters it's function and initiates the cell to advance to the next phase. (jove.com)
  • 1) The regulation of these protein levels is vital for the understanding of the cell cycle control and its dysregulation. (ukessays.com)
  • 2) Therefore, the proper control of protein levels is crucial for the cell cycle. (ukessays.com)
  • To do so, we model the cell cycle as a partially temporal network of protein-protein interactions (PPIs) by combining a traditional static PPI network with protein concentration or RNA expression time series data. (biorxiv.org)
  • As a result, the glycolysis pathway in diabetic HepG2 cells was accelerated by the Hypoxia-Induced Factor (HIF), which was preceded by galactolysis. (pulsus.com)
  • A greater activity of the Leloir pathway in OXPHOS cells was clearly matched by an increase in the glycolytic flux under hypoxia. (pulsus.com)
  • During cell growth and proliferation, ubiquitin plays an outsized role in promoting progression through the cell cycle. (intechopen.com)
  • Progression through the cell cycle is driven by the oscillating activity of Cyclin Dependent Kinases (CDKs). (intechopen.com)
  • The model accounts for important details of the physiology, biochemistry, and genetics of cell cycle control in stalked C. crescentus cell. (ebi.ac.uk)
  • Because of its mutated aggressive genetics, this cell has a selective growth advantage over its neighbors. (medscape.com)
  • The cell cycle, or cell-division cycle, is the series of events that take place in a cell that causes it to divide into two daughter cells. (wikipedia.org)
  • These events include the duplication of its DNA (DNA replication) and some of its organelles, and subsequently the partitioning of its cytoplasm, chromosomes and other components into two daughter cells in a process called cell division. (wikipedia.org)
  • The B period extends from the end of cell division to the beginning of DNA replication. (wikipedia.org)
  • In single-celled organisms, a single cell-division cycle is how the organism replicates itself. (wikipedia.org)
  • cell cycle , the ordered sequence of events that occur in a cell in preparation for cell division . (britannica.com)
  • For a stimulatory signal to reach the nucleus and "turn on" cell division, four main steps must occur. (britannica.com)
  • Progression of a cell through the division cycle is tightly controlled at different steps to ensure the integrity of genome replication and partitioning to daughter cells. (ebi.ac.uk)
  • From published experimental evidence, we propose a molecular mechanism for control of the cell division cycle in Caulobacter crescentus. (ebi.ac.uk)
  • Although not a traditional experimental "method," mathematical modeling can provide a powerful approach for investigating complex cell signaling networks, such as those that regulate the eukaryotic cell division cycle. (nih.gov)
  • The cell cycle is a series of carefully regulated events, including periods of growth, rest, and cell division. (coursehero.com)
  • Most cells spend nearly all of their time in this part of cell division, growing in size and carrying out the normal functions of the cell. (coursehero.com)
  • When the cell receives signals for division, it moves to the S phase. (coursehero.com)
  • During the G2 phase, a structure in the cytoplasm of animal cells that coordinates the formation of microtubules, called a centrosome , allows cell division to proceed during reproduction. (coursehero.com)
  • In particular, it pursues a complex lifecycle with modes of cell division that differ at different lifecycle stages. (europa.eu)
  • In schizogony a single parasite first generates many nuclei via independent, asynchronous rounds of genome replication, prior to cytokinesis which is the physical division of the cell. (europa.eu)
  • Thus, schizogony challenges some basic paradigms about DNA replication control, while gametogenesis demands a speed of DNA replication and cell division that is unprecedented in eukaryotic gametogenesis. (europa.eu)
  • The molecular processes behind cell cycle progression have been dissected by numerous morphological studies on live or fixed single cells using a plethora of techniques to visualize components and processes during cell division. (frontiersin.org)
  • Such data are only indirectly related to quantitative changes in cells at different states of division and growth. (frontiersin.org)
  • In this lab experience, students explore the consequences of uncontrolled cell division. (flinnsci.com)
  • The cell division cycle is the process in which the entirety of a cell's contents is duplicated completely and then equally segregated into two identical daughter cells. (duke.edu)
  • as they undergo cell division. (lu.se)
  • Packed red cells are processed, stored, and shipped to the Division of Environmental Health Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention for analysis. (cdc.gov)
  • First, a growth factor must bind to its receptor on the cell membrane . (britannica.com)
  • However, proliferative indices alone do not suffice to characterise cell growth. (bmj.com)
  • Clonal growth in primary SAEC cells was increased by 0.024 and 0.24 microg/mL HTMW and NDMW and 2.4 microg/mL HTMW. (cdc.gov)
  • Initial exponential tumor growth is followed by a plateau phase when cell death nearly equals the rate of formation of daughter cells. (msdmanuals.com)
  • In cells without nuclei (prokaryotes, i.e., bacteria and archaea), the cell cycle is divided into the B, C, and D periods. (wikipedia.org)
  • It combines image analysis and machine learning methods for automated 3D segmentation and cell-cycle state identification of individual cell-nuclei with widely varying morphologies embedded in complex tumor environments. (nature.com)
  • Figure 2: Automatic segmentation of cell nuclei. (nature.com)
  • Timecourses have been conducted to quantify the number and type of replicating nuclei, together with other cell-biological features, in P. falciparum parasites across the course of both erythrocytic schizogony and gametogenesis. (europa.eu)
  • Biological data points to additional couplings, including a link back from the cell cycle to the circadian clock. (dagstuhl.de)
  • Night shift workers might also have an increased risk for reproductive issues, such as irregular menstrual cycles, miscarriage, and preterm birth. (cdc.gov)
  • This process is assumed to be under the control of the cell cycle, because of how closely linked to the S phase histone synthesis is. (news-medical.net)
  • The data suggest that Sp3 may contribute to the control of proliferation- and/or cell-regulated promoters depending upon the context and/or number of functional Sp1 binding sites. (nih.gov)
  • Checkpoint control kinases is a term used to describe a group of enzymes that regulate progression of a cell through the cell cycle. (tocris.com)
  • Checkpoint control kinases function to halt the cell cycle at these critical points. (tocris.com)
  • Medulloblastoma cell line D341 was cultured and divided into control group, low dose group, medium dose group and high dose group. (ijpsonline.com)
  • MicroRNAs control the levels of numerous cell cycle regulators that controls cell proliferation. (ukessays.com)
  • Regulatory signaling systems that control the progression of the CELL CYCLE through the G1 PHASE and allow transition to S PHASE when the cells are ready to undergo DNA REPLICATION. (umassmed.edu)
  • The PUUV strain Kazan wild type (PUUV Kazan-wt) ( 7 , 8 ) was used for subcutaneous inoculation of bank voles, and Vero E6 cell line-adapted PUUV strain Kazan (PUUV Kazan-E6) ( 7 ) was used in inhibition experiments and as a positive control in the real-time RT-PCR. (cdc.gov)
  • Many cells do not enter G0 and continue to divide throughout an organism's life, e.g., epithelial cells. (wikipedia.org)
  • To investigate genotoxicity of NDMW and HTMW compared to PMW we used two human lung epithelial cell types, an immortalized BEAS-2B and primary SAEC. (cdc.gov)
  • [ 7 ] Similarly, in 2001, Priolo and Laganà reclassified the ectodermal dysplasias into 2 main functional groups: (1) defects in developmental regulation/epithelial-mesenchymal interaction and (2) defects in cytoskeleton maintenance and cell stability. (medscape.com)
  • If AD neurons in-vivo died as soon as 12 hours after entry into the cell cycle (as shown in vitro and in developing mouse brain in vivo), and five percent of cells were dying at any one time (as shown in this study), then it would take less than a year for complete neuronal ablation. (alzforum.org)
  • We investigated the effects of various concentrations of Tan IIA (5-10 μ g/mL) on mouse keratinocytes and human HaCat cells in vitro to confirm this hypothesis. (hindawi.com)
  • An image depicting head and neck squamous cell carcinoma in vitro can be seen below. (medscape.com)
  • Head and neck squamous cell carcinoma in vitro (cell culture). (medscape.com)
  • 2003), Depletion of the cell-cycle inhibitor p27(Xic1). (xenbase.org)
  • In 2003, Lamartine reclassified the ectodermal dysplasias into the following 4 functional groups based on the underlying pathophysiologic defect: (1) cell-to-cell communication and signaling, (2) adhesion, (3) development, and (4) other. (medscape.com)
  • [ 8 ] Other classification systems categorize the ectodermal dysplasias based on defects in cell-cell communication and signaling, adhesion, transcription regulation, or development. (medscape.com)
  • The paper proposes that cell cycle reentry is a central mechanistic feature of AD throughout the disease process, not just a rare aberration in the latest stages. (alzforum.org)
  • However fast these neurons die, the paper states that neurons die at the same rate in all stages of the disease process, and that neurons die from the same root cause (i.e., cell cycle reentry) throughout the disease. (alzforum.org)
  • We found that ParA:ParB ratios fluctuate between predation stages, their balance being critical for cell cycle progression. (jic.ac.uk)
  • Liver-specific pRB loss results in ectopic cell cycle entry and aberrant ploidy. (nature.com)
  • Taken together with the positive results in many different neuronal populations, this study arrives at the conclusion that ectopic reentrance into the cell cycle is a "unified" mechanism of neurodegeneration, indicative of a "single disease process" in all neurons in many disease states. (alzforum.org)
  • To develop a data-driven model of cell cycle regulation, we used contiguous, dynamic measurements over two time scales (minutes and hours) calculated from static multiparametric cytometry data. (ebi.ac.uk)
  • This result fits with the second model of cell-cycle regulation. (duke.edu)
  • In particular, ubiquitin-mediated degradation is critically important at transition points where it provides directionality and irreversibility to the cell cycle, which is essential for maintaining genome integrity. (intechopen.com)
  • Malaria parasites replicate inside the cells of their human host via 'schizogony', which is fundamentally different from conventional binary fission - the replication mode used by most cells from human cells to yeast cells. (europa.eu)
  • Here, we recover the temporal organisation of the cell cycle of budding yeast into phases and subphases, in an automated way. (biorxiv.org)
  • Third, this activation must stimulate a signal to be transmitted, or transduced, from the receptor at the cell surface to the nucleus within the cell. (britannica.com)
  • The authors found a similar pattern in cells outside the hippocampus, such as in the entorhinal cortex and the nucleus basalis of Meynert, areas where AD-related cell cycle reentry has previously been documented. (alzforum.org)
  • Using antibodies specific for Sp1 and Sp3, we observe that both of these factors localize to the cell nucleus and have a similar, dispersed subnuclear distribution. (nih.gov)
  • The cell replicates its DNA, forming sister chromatids. (coursehero.com)
  • HIV preferentially infects and replicates in cells expressing the CD4 molecule, the ligand for viral attachment and subsequent cell entry (1). (cdc.gov)
  • Downloaded from periodic thymic colonization by progenitor cells guarantees stage. (lu.se)
  • The immediate partial restoration of respiration upon addition of membrane-permeant dimethyl-2- oxoglutarate to inhibited cells demonstrated the absence of 2OGdehydrogenase substrate post aminotransferase inhibition.Surprisingly, the AOA (bithionol) inhibition stopped after 72 hours of 5% O2 hypoxia, and respiration was fully recovered. (pulsus.com)
  • However, several studies have shown that some cell-cycle events, such as periodic transcription, can continue in the absence of CDK activity. (duke.edu)
  • How are periodic transcription and other cell-cycle events coupled to each other during a wild-type cell cycle? (duke.edu)
  • One model hypothesizes that oscillations in CDK activity controls the timing of cell-cycle events, including periodic transcription. (duke.edu)
  • The second model proposes that a transcription factor (TF) network oscillator controls the timing of cell-cycle events, via proper timing of gene expression, including cyclins. (duke.edu)
  • By measuring global gene expression dynamics in cells with persistent CDK activity, I show that periodic transcription continues. (duke.edu)
  • Cells that have temporarily or reversibly stopped dividing are said to have entered a state of quiescence called G0 phase. (wikipedia.org)
  • G0 is a resting phase where the cell has left the cycle and has stopped dividing. (wikipedia.org)
  • The cell cycle starts with this phase. (wikipedia.org)
  • During this phase, the biosynthetic activities of the cell, which are considerably slowed down during M phase, resume at a high rate. (wikipedia.org)
  • Upregulation of histone gene expression is one of the hallmarks of entry into the cell cycle's S phase. (news-medical.net)
  • Entry into the S phase in animal cells is regulated to a large extent by the cyclin E-CDK2 kinase complex. (news-medical.net)
  • Cells increase in size during G1 phase, which is followed by DNA replication in S phase. (novusbio.com)
  • When cells are not actively dividing they are considered to be in a state of quiescence, known as the G0 phase. (novusbio.com)
  • Catastrophic genetic damage can occur if cells progress to the next phase of the cell cycle before the previous phase is properly completed. (tocris.com)
  • For instance, during G1, when one type of cyclin, named D, is synthesized and binds to a CDK, the cell transitions into S phase, as another cyclin, E, peaks and forms a complex with CDK to promote DNA replication. (jove.com)
  • Cyclins can be categorized as G 1 , G 1 /S, S, or M cyclins based on the cell cycle phase or transition they are most involved in. (jove.com)
  • and the M phase, the fourth phase of the cell cycle, when a cell divides. (coursehero.com)
  • A cell can remain in the G0 phase indefinitely, awaiting a signal to return to the normal cell cycle. (coursehero.com)
  • The amount of time spent in any given phase of the cell cycle is dependent upon the type of cell and the environmental conditions in which the cell lives. (coursehero.com)
  • The length of this particular phase is the most variable among different cell types. (coursehero.com)
  • Once the DNA has been replicated, the cell moves to the second gap phase. (coursehero.com)
  • By applying the random forests algorithm, a supervised machine learning approach, we show how a multi-gene signature that classifies individual cells into their correct cell cycle phase and cell size can be generated. (frontiersin.org)
  • Some drugs work only during a specific phase of the cell cycle, requiring prolonged administration to catch dividing cells during the phase of maximal sensitivity. (msdmanuals.com)
  • Visualizing spatiotemporal dynamics of multicellular cell-cycle progression. (nature.com)
  • This project is elucidating the spatio-temporal dynamics of DNA replication in these contrasting cell cycles. (europa.eu)
  • Most studies have been performed on large cell populations, but detailed understanding of cell dynamics and heterogeneity requires single-cell analysis. (frontiersin.org)
  • I will present an all-in-one cell cycle reporter that allows simultaneous analysis of cell cycle progression, including the transition into quiescence, and the dynamics of individual fate determinants. (cam.ac.uk)
  • Our study reveals the subcellular dynamics and multi-layered regulation of the ParABS system, coupled to the cell cycle of B. bacteriovorus. (jic.ac.uk)
  • Then, we cluster the snapshots of this temporal network to infer phases, which show good agreement with our biological knowledge of the cell cycle. (biorxiv.org)
  • and regulation of cell cycle process. (nih.gov)
  • This study aimed to explore the potential targets and molecular mechanisms of HNK on metastatic BCSC (mBCSC)-cell cycle arrest and the impact of the TME. (hindawi.com)
  • Finally, the interaction between HNK and two HNK-targets regulating the cell cycle was analyzed using molecular docking analysis. (hindawi.com)
  • The identified potential therapeutic targets of HNK (PTTH) included CCND1 , SIRT2 , AURKB , VEGFA , HDAC1 , CASP9 , HSP90AA1 , and HSP90AB1 , which can potentially inhibit the cell cycle of mBCSCs. (hindawi.com)
  • Surprisingly, CD4+ T cell lines from acutely and persistently EBV-infected donors consistently responded against EBV lytic cycle antigens and autoantigens, but barely against latent cycle antigens of EBV hitherto considered principal immunotherapeutic targets. (uni-muenchen.de)
  • These results indicate that structural antigens of EBV are the immunodominant targets of CD4+ T cells in LCL-stimulated T cell preparations. (uni-muenchen.de)
  • In this chapter, we mainly discuss the coordination regulations between DNA replication initiation and other cell cycle events that ensure genomic integrity. (intechopen.com)
  • Any DNA replication initiation that is involved in cell cycle DNA replication. (mcw.edu)
  • The cell cycle consists of four phases (G1, S, G2 and M), all of which are characterized by different factors. (news-medical.net)
  • Here, we present an integrated workflow for quantitative in vivo cell-cycle profiling. (nature.com)
  • Figure 4: Quantitative analysis of drug response to paclitaxel treatment at a single-cell level. (nature.com)
  • For a quantitative comparison, the authors counted cell cycle-positive neurons in the hippocampal samples. (alzforum.org)
  • Several of these processes change during the cell cycle, but unlike transcriptional changes, the post-translational changes occur throughout the cell cycle. (news-medical.net)
  • The venture has executed an agreement with Canadian company Li-Cycle to recycle critical materials from the scrap produced from Ultium's manufacturing processes from its Lordstown plant, starting later in 2021. (techcrunch.com)
  • Non-proliferative (non-dividing) cells in multicellular eukaryotes generally enter the quiescent G0 state from G1 and may remain quiescent for long periods of time, possibly indefinitely (as is often the case for neurons). (wikipedia.org)
  • On the basis of the stimulatory and inhibitory messages a cell receives, it "decides" whether it should enter the cell cycle and divide. (britannica.com)
  • once complete, the cell is ready to divide. (coursehero.com)
  • Accepted: 24 October 2012 cell yield data, our models require that adult DN1 cells divide multiple times before becoming competent to progress into DN2 stage. (lu.se)
  • Obviously, this is not the case, leading Yang and colleagues to posit that these neurons are probably stuck for months or even a year in a cell cycle they cannot complete, and that they may not die by a typical apoptotic process. (alzforum.org)
  • The presence of cell cycle markers in every one of the 10 MCI cases studied signifies a role for a cell cycle-driven process, not only in AD, but in other age-associated dementias, as well. (alzforum.org)
  • The cell cycle is the process of accurate self-reproduction and proliferation of a cell. (intechopen.com)
  • To consistently produce healthy cells, the cell cycle-the process that generates daughter cells-must be precisely regulated. (jove.com)
  • Li-Cycle uses a low-temperature mechanical process that shreds - actually shreds, like a paper shredder - the battery materials in a submerged, proprietary solution. (techcrunch.com)
  • Once the Arizona facility becomes operational, Li-Cycle will be able to process around 20,000 metric tons, or 4 gigawatt-hours, of lithium-ion batteries annually. (techcrunch.com)
  • However, it is not known if Li-Cycle will process waste from this plant, too. (techcrunch.com)

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