The phase of cell nucleus division following METAPHASE, in which the CHROMATIDS separate and migrate to opposite poles of the spindle.
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.
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.
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.
The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.
The final phase of cell nucleus division following ANAPHASE, in which two daughter nuclei are formed, the CYTOPLASM completes division, and the CHROMOSOMES lose their distinctness and are transformed into CHROMATIN threads.
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.
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).
Separase is a caspase-like cysteine protease, which plays a central role in triggering ANAPHASE by cleaving the SCC1/RAD21 subunit of the cohesin complex. Cohesin holds the sister CHROMATIDS together during METAPHASE and its cleavage results in chromosome segregation.
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.
Either of the two longitudinally adjacent threads formed when a eukaryotic chromosome replicates prior to mitosis. The chromatids are held together at the centromere. Sister chromatids are derived from the same chromosome. (Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Securin is involved in the control of the metaphase-anaphase transition during MITOSIS. It promotes the onset of anaphase by blocking SEPARASE function and preventing proteolysis of cohesin and separation of sister CHROMATIDS. Overexpression of securin is associated with NEOPLASTIC CELL TRANSFORMATION and tumor formation.
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.
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Highly conserved proteins that specifically bind to and activate the anaphase-promoting complex-cyclosome, promoting ubiquitination and proteolysis of cell-cycle-regulatory proteins. Cdc20 is essential for anaphase-promoting complex activity, initiation of anaphase, and cyclin proteolysis during mitosis.
The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.
The process by which the CYTOPLASM of a cell is divided.
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.
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.
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 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.
A family of highly conserved serine-threonine kinases that are involved in the regulation of MITOSIS. They are involved in many aspects of cell division, including centrosome duplication, SPINDLE APPARATUS formation, chromosome alignment, attachment to the spindle, checkpoint activation, and CYTOKINESIS.
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.
A microtubule-associated mechanical adenosine triphosphatase, that uses the energy of ATP hydrolysis to move organelles along microtubules toward the plus end of the microtubule. The protein is found in squid axoplasm, optic lobes, and in bovine brain. Bovine kinesin is a heterotetramer composed of two heavy (120 kDa) and two light (62 kDa) chains. EC 3.6.1.-.
The first phase of cell nucleus division, in which the CHROMOSOMES become visible, the CELL NUCLEUS starts to lose its identity, the SPINDLE APPARATUS appears, and the CENTRIOLES migrate toward opposite poles.
Nocodazole is an antineoplastic agent which exerts its effect by depolymerizing microtubules.
Cdh1 is an activator of the anaphase-promoting complex-cyclosome, and is involved in substrate recognition. It associates with the complex in late MITOSIS from anaphase through G1 to regulate activity of CYCLIN-DEPENDENT KINASES and to prevent premature DNA replication.
Proteins found in any species of fungus.
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.
The phase of cell nucleus division following PROPHASE, when the breakdown of the NUCLEAR ENVELOPE occurs and the MITOTIC SPINDLE APPARATUS enters the nuclear region and attaches to the KINETOCHORES.
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.
An aurora kinase that is a component of the chromosomal passenger protein complex and is involved in the regulation of MITOSIS. It mediates proper CHROMOSOME SEGREGATION and contractile ring function during CYTOKINESIS.
Male germ cells derived from SPERMATOGONIA. The euploid primary spermatocytes undergo MEIOSIS and give rise to the haploid secondary spermatocytes which in turn give rise to SPERMATIDS.
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.
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 genus of ascomycetous fungi of the family Schizosaccharomycetaceae, order Schizosaccharomycetales.
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.
A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.
The cellular signaling system that halts the progression of cells through MITOSIS or MEIOSIS if a defect that will affect CHROMOSOME SEGREGATION is detected.
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).
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).
A family of herbivorous leaping MAMMALS of Australia, New Guinea, and adjacent islands. Members include kangaroos, wallabies, quokkas, and wallaroos.
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.
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.
An order of fungi in the phylum Ascomycota that multiply by budding. They include the telomorphic ascomycetous yeasts which are found in a very wide range of habitats.
A class of enzymes that catalyze the formation of a bond between two substrate molecules, coupled with the hydrolysis of a pyrophosphate bond in ATP or a similar energy donor. (Dorland, 28th ed) EC 6.
Together with the Apc11 subunit, forms the catalytic core of the E3 ubiquitin ligase anaphase-promoting complex (APC-C). Its N-terminus has cullin domains which associate with the RING FINGER DOMAINS of Apc11. Apc2 also interacts with the E2 ubiquitin ligases involved in APC-C ubiquitination reactions.
The failure of homologous CHROMOSOMES or CHROMATIDS to segregate during MITOSIS or MEIOSIS with the result that one daughter cell has both of a pair of parental chromosomes or chromatids and the other has none.
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.
Structures within the nucleus of fungal cells consisting of or containing DNA, which carry genetic information essential to the cell.
Very long DNA molecules and associated proteins, HISTONES, and non-histone chromosomal proteins (CHROMOSOMAL PROTEINS, NON-HISTONE). Normally 46 chromosomes, including two sex chromosomes are found in the nucleus of human cells. They carry the hereditary information of the individual.
A family of multisubunit cytoskeletal motor proteins that use the energy of ATP hydrolysis to power a variety of cellular functions. Dyneins fall into two major classes based upon structural and functional criteria.
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.
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 highly conserved subunit of the anaphase-promoting complex (APC-C) containing multiple 34-amino-acid tetratricopeptide repeats. These domains, also found in Apc3, Apc6, and Apc7, have been shown to mediate protein-protein interactions, suggesting that Apc8 may assist in coordinating the juxtaposition of the catalytic and substrate recognition module subunits relative to coactivators and APC-C inhibitors.
A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.
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).
A family of rat kangaroos found in and around Australia. Genera include Potorous and Bettongia.
CIRCULAR DNA that is interlaced together as links in a chain. It is used as an assay for the activity of DNA TOPOISOMERASES. Catenated DNA is attached loop to loop in contrast to CONCATENATED DNA which is attached end to end.
Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)
A genus of the family Heteromyidae which contains 22 species. Their physiology is adapted for the conservation of water, and they seldom drink water. They are found in arid or desert habitats and travel by hopping on their hind limbs.
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)
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.
An exchange of segments between the sister chromatids of a chromosome, either between the sister chromatids of a meiotic tetrad or between the sister chromatids of a duplicated somatic chromosome. Its frequency is increased by ultraviolet and ionizing radiation and other mutagenic agents and is particularly high in BLOOM SYNDROME.
An enzyme group that specifically dephosphorylates phosphotyrosyl residues in selected proteins. Together with PROTEIN-TYROSINE KINASE, it regulates tyrosine phosphorylation and dephosphorylation in cellular signal transduction and may play a role in cell growth control and carcinogenesis.
The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).
An order of the class Insecta. Wings, when present, number two and distinguish Diptera from other so-called flies, while the halteres, or reduced hindwings, separate Diptera from other insects with one pair of wings. The order includes the families Calliphoridae, Oestridae, Phoridae, SARCOPHAGIDAE, Scatophagidae, Sciaridae, SIMULIIDAE, Tabanidae, Therevidae, Trypetidae, CERATOPOGONIDAE; CHIRONOMIDAE; CULICIDAE; DROSOPHILIDAE; GLOSSINIDAE; MUSCIDAE; TEPHRITIDAE; and PSYCHODIDAE. The larval form of Diptera species are called maggots (see LARVA).
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.
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.
An increased tendency to acquire CHROMOSOME ABERRATIONS when various processes involved in chromosome replication, repair, or segregation are dysfunctional.
Microscopy in which television cameras are used to brighten magnified images that are otherwise too dark to be seen with the naked eye. It is used frequently in TELEPATHOLOGY.
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).
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.
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.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
A family of Urodela consisting of 15 living genera and about 42 species and occurring in North America, Europe, Asia, and North Africa.
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.
A broad category of nuclear proteins that are components of or participate in the formation of the NUCLEAR MATRIX.
Proteins to which calcium ions are bound. They can act as transport proteins, regulator proteins, or activator proteins. They typically contain EF HAND MOTIFS.
The performance of dissections, injections, surgery, etc., by the use of micromanipulators (attachments to a microscope) that manipulate tiny instruments.
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.
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.
Macromolecular complexes formed from the association of defined protein subunits.
The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.
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.
The chromosomal constitution of a cell containing multiples of the normal number of CHROMOSOMES; includes triploidy (symbol: 3N), tetraploidy (symbol: 4N), etc.
A systemic agricultural fungicide used for control of certain fungal diseases of stone fruit.
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
The recording of wavelike motions or undulations. It is usually used on arteries to detect variations in blood pressure.
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
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 mature haploid female germ cell extruded from the OVARY at OVULATION.
The membrane system of the CELL NUCLEUS that surrounds the nucleoplasm. It consists of two concentric membranes separated by the perinuclear space. The structures of the envelope where it opens to the cytoplasm are called the nuclear pores (NUCLEAR PORE).
An alkaloid isolated from Colchicum autumnale L. and used as an antineoplastic.
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.
Plant-eating orthopterans having hindlegs adapted for jumping. There are two main families: Acrididae and Romaleidae. Some of the more common genera are: Melanoplus, the most common grasshopper; Conocephalus, the eastern meadow grasshopper; and Pterophylla, the true katydid.
The mechanisms of eukaryotic CELLS that place or keep the CHROMOSOMES in a particular SUBNUCLEAR SPACE.
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.
The largest subunit of the anaphase-promoting complex. It acts primarily as a scaffold for the proper organization and arrangement of subunits. The C-terminal region of Apc1 contains a series of tandem amino acid repeats that are also seen in the 26S proteasome regulatory particle, and may assist with forming and stabilizing protein-protein interactions.

Evidence for a relatively random array of human chromosomes on the mitotic ring. (1/1090)

We used fluorescence in situ hybridization (FISH) to study the positions of human chromosomes on the mitotic rings of cultured human lymphocytes, MRC-5 fibroblasts, and CCD-34Lu fibroblasts. The homologous chromosomes of all three cell types had relatively random positions with respect to each other on the mitotic rings of prometaphase rosettes and anaphase cells. Also, the positions of the X and Y chromosomes, colocalized with the somatic homologues in male cells, were highly variable from one mitotic ring to another. Although random chromosomal positions were found in different pairs of CCD-34Lu and MRC-5 late-anaphases, the separations between the same homologous chromosomes in paired late-anaphase and telophase chromosomal masses were highly correlated. Thus, although some loose spatial associations of chromosomes secondary to interphase positioning may exist on the mitotic rings of some cells, a fixed order of human chromosomes and/or a rigorous separation of homologous chromosomes on the mitotic ring are not necessary for normal mitosis. Furthermore, the relative chromosomal positions on each individual metaphase plate are most likely carried through anaphase into telophase.  (+info)

Ctf19p: A novel kinetochore protein in Saccharomyces cerevisiae and a potential link between the kinetochore and mitotic spindle. (2/1090)

A genetic synthetic dosage lethality (SDL) screen using CTF13 encoding a known kinetochore protein as the overexpressed reference gene identified two chromosome transmission fidelity (ctf) mutants, YCTF58 and YCTF26. These mutant strains carry independent alleles of a novel gene, which we have designated CTF19. In light of its potential role in kinetochore function, we have cloned and characterized the CTF19 gene in detail. CTF19 encodes a nonessential 369-amino acid protein. ctf19 mutant strains display a severe chromosome missegregation phenotype, are hypersensitive to benomyl, and accumulate at G2/M in cycling cells. CTF19 genetically interacts with kinetochore structural mutants and mitotic checkpoint mutants. In addition, ctf19 mutants show a defect in the ability of centromeres on minichromosomes to bind microtubules in an in vitro assay. In vivo cross-linking and chromatin immunoprecipitation demonstrates that Ctf19p specifically interacts with CEN DNA. Furthermore, Ctf19-HAp localizes to the nuclear face of the spindle pole body and genetically interacts with a spindle-associated protein. We propose that Ctf19p is part of a macromolecular kinetochore complex, which may function as a link between the kinetochore and the mitotic spindle.  (+info)

Phosphorylation-induced rearrangement of the histone H3 NH2-terminal domain during mitotic chromosome condensation. (3/1090)

The NH2-terminal domain (N-tail) of histone H3 has been implicated in chromatin compaction and its phosphorylation at Ser10 is tightly correlated with mitotic chromosome condensation. We have developed one mAb that specifically recognizes histone H3 N-tails phosphorylated at Ser10 (H3P Ab) and another that recognizes phosphorylated and unphosphorylated H3 N-tails equally well (H3 Ab). Immunocytochemistry with the H3P Ab shows that Ser10 phosphorylation begins in early prophase, peaks before metaphase, and decreases during anaphase and telophase. Unexpectedly, the H3 Ab shows stronger immunofluorescence in mitosis than interphase, indicating that the H3 N-tail is more accessible in condensed mitotic chromatin than in decondensed interphase chromatin. In vivo ultraviolet laser cross-linking indicates that the H3 N-tail is bound to DNA in interphase cells and that binding is reduced in mitotic cells. Treatment of mitotic cells with the protein kinase inhibitor staurosporine causes histone H3 dephosphorylation and chromosome decondensation. It also decreases the accessibility of the H3 N-tail to H3 Ab and increases the binding of the N-tail to DNA. These results indicate that a phosphorylation-dependent weakening of the association between the H3 N-tail and DNA plays a role in mitotic chromosome condensation.  (+info)

ASH1 mRNA localization in yeast involves multiple secondary structural elements and Ash1 protein translation. (4/1090)

Localization of ASH1 mRNA to the distal cortex of daughter but not mother cells at the end of anaphase is responsible for the two cells' differential mating-type switching during the subsequent cell cycle. This localization depends on actin filaments and a type V myosin (She1/Myo4). The 3' untranslated region (3' UTR) of ASH1 mRNA is reportedly capable of directing heterologous RNAs to a mother cell's bud [1] [2]. Surprisingly, however, its replacement has little or no effect on the localisation of ASH1 mRNA. We show here that, unlike all other known localization sequences that have been found in 3' UTRs, all the elements involved in ASH1 mRNA localization are located at least partly within its coding region. A 77 nucleotide region stretching from 7 nucleotides 5' to 67 nucleotides 3' of the stop codon of ASH1 mRNA is sufficient to localize mRNAs to buds; the secondary structure of this region, in particular two stems, is important for its localizing activity. Two regions entirely within coding sequences, both sufficient to localize green fluorescent protein (GFP) mRNA to growing buds, are necessary for ASH1 mRNA localization during anaphase. These three regions can anchor GFP mRNA to the distal cortex of daughter cells only inefficiently. The tight anchoring of ASH1 mRNA to the cortex of the daughter cell depends on translation of the carboxy-terminal sequences of Ash1 protein.  (+info)

Structural elements required for the localization of ASH1 mRNA and of a green fluorescent protein reporter particle in vivo. (5/1090)

The sorting of the Ash1 protein to the daughter nucleus of Saccharomyces cerevisiae in late anaphase of the budding cycle correlates with the localization of ASH1 mRNA at the bud tip [1] [2]. Although the 3' untranslated region (3' UTR) of ASH1 is sufficient to localize a reporter mRNA, it is not necessary, a result which indicates that other sequences are involved [1]. We report the identification of three additional cis-acting elements in the coding region. Each element alone, when fused to a lacZ reporter gene, was sufficient for the localization of the lacZ mRNA reporter to the bud. A fine-structure analysis of the 3' UTR element showed that its function in mRNA localization did not depend on a specific sequence but on the secondary and tertiary structure of a minimal 118 nucleotide stem-loop. Mutations in the stem-loop that affect the localization of the lacZ mRNA reporter also affected the formation of the localization particles, in living cells, composed of a green fluorescent protein (GFP) complexed with lacZ-ASH1-3' UTR mRNA [3]. A specific stem-loop in the 3' UTR of the ASH1 mRNA is therefore required for both localization and particle formation, suggesting that complex formation is part of the localization mechanism. An analysis on one of the coding-region elements revealed a comparable stem-loop structure with similar functional requirements.  (+info)

The Pds1 anaphase inhibitor and Mec1 kinase define distinct checkpoints coupling S phase with mitosis in budding yeast. (6/1090)

In most eukaryotic cells, DNA replication is confined to S phase of the cell cycle [1]. During this interval, S-phase checkpoint controls restrain mitosis until replication is complete [2]. In budding yeast, the anaphase inhibitor Pds1p has been associated with the checkpoint arrest of mitosis when DNA is damaged or when mitotic spindles have formed aberrantly [3] [4], but not when DNA replication is blocked with hydroxyurea (HU). Previous studies have implicated the protein kinase Mec1p in S-phase checkpoint control [5]. Unlike mec1 mutants, pds1 mutants efficiently inhibit anaphase when replication is blocked. This does not, however, exclude an essential S-phase checkpoint function of Pds1 beyond the early S-phase arrest point of a HU block. Here, we show that Pds1p is an essential component of a previously unsuspected checkpoint control system that couples the completion of S phase with mitosis. Further, the S-phase checkpoint comprises at least two distinct pathways. A Mec1p-dependent pathway operates early in S phase, but a Pds1p-dependent pathway becomes essential part way through S phase.  (+info)

The maize homologue of the cell cycle checkpoint protein MAD2 reveals kinetochore substructure and contrasting mitotic and meiotic localization patterns. (7/1090)

We have identified a maize homologue of yeast MAD2, an essential component in the spindle checkpoint pathway that ensures metaphase is complete before anaphase begins. Combined immunolocalization of MAD2 and a recently cloned maize CENPC homologue indicates that MAD2 localizes to an outer domain of the prometaphase kinetochore. MAD2 staining was primarily observed on mitotic kinetochores that lacked attached microtubules; i.e., at prometaphase or when the microtubules were depolymerized with oryzalin. In contrast, the loss of MAD2 staining in meiosis was not correlated with initial microtubule attachment but was correlated with a measure of tension: the distance between homologous or sister kinetochores (in meiosis I and II, respectively). Further, the tension-sensitive 3F3/2 phosphoepitope colocalized, and was lost concomitantly, with MAD2 staining at the meiotic kinetochore. The mechanism of spindle assembly (discussed here with respect to maize mitosis and meiosis) is likely to affect the relative contributions of attachment and tension. We support the idea that MAD2 is attachment-sensitive and that tension stabilizes microtubule attachments.  (+info)

A Bub2p-dependent spindle checkpoint pathway regulates the Dbf2p kinase in budding yeast. (8/1090)

Exit from mitosis in all eukaroytes requires inactivation of the mitotic kinase. This occurs principally by ubiquitin-mediated proteolysis of the cyclin subunit controlled by the anaphase-promoting complex (APC). However, an abnormal spindle and/or unattached kinetochores activates a conserved spindle checkpoint that blocks APC function. This leads to high mitotic kinase activity and prevents mitotic exit. DBF2 belongs to a group of budding yeast cell cycle genes that when mutated prevent cyclin degradation and block exit from mitosis. DBF2 encodes a protein kinase which is cell cycle regulated, peaking in metaphase-anaphase B/telophase, but its function remains unknown. Here, we show the Dbf2p kinase activity to be a target of the spindle checkpoint. It is controlled specifically by Bub2p, one of the checkpoint components that is conserved in fission yeast and higher eukaroytic cells. Significantly, in budding yeast, Bub2p shows few genetic or biochemical interactions with other members of the spindle checkpoint. Our data now point to the protein kinase Mps1p triggering a new parallel branch of the spindle checkpoint in which Bub2p blocks Dbf2p function.  (+info)

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 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.

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.

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.

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.

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.

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.

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.

Separase is not a medical term itself, but it is a biological term used in the field of cell biology and genetics. Separase is an enzyme that plays a crucial role in the separation of chromosomes during cell division (mitosis and meiosis).

In more detail, separase is a protease enzyme that contributes to the breakdown of cohesin complexes, which are protein structures that hold sister chromatids together after DNA replication. Separase's function is essential for the proper separation of chromosomes during anaphase, the stage of mitosis where sister chromatids are pulled apart and moved to opposite poles of the cell.

While not a medical term per se, understanding separase and its role in cell division can help researchers better understand certain genetic disorders or diseases that may be caused by errors in cell division.

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.

Chromatids are defined as the individual strands that make up a duplicated chromosome. They are formed during the S phase of the cell cycle, when replication occurs and each chromosome is copied, resulting in two identical sister chromatids. These chromatids are connected at a region called the centromere and are held together by cohesin protein complexes until they are separated during mitosis or meiosis.

During mitosis, the sister chromatids are pulled apart by the mitotic spindle apparatus and distributed equally to each daughter cell. In meiosis, which is a type of cell division that occurs in the production of gametes (sex cells), homologous chromosomes pair up and exchange genetic material through a process called crossing over. After crossing over, each homologous chromosome consists of two recombinant chromatids that are separated during meiosis I, and then sister chromatids are separated during meiosis II.

Chromatids play an essential role in the faithful transmission of genetic information from one generation to the next, ensuring that each daughter cell or gamete receives a complete set of chromosomes with intact and functional genes.

Securin is not a medical term, but rather a biological concept related to cell division. It's a protein that plays a crucial role in the regulation of chromosome separation during cell division (mitosis).

During mitosis, sister chromatids (identical copies of a chromosome) are held together by cohesin proteins until it's time for them to separate and move to opposite ends of the cell. Securin is one of the proteins that helps regulate this process. Specifically, securin inhibits an enzyme called separase, which is responsible for cleaving the cohesin rings that hold sister chromatids together.

Once the cell is ready to separate its chromosomes, a protease called separase is activated and degrades securin. This allows separase to cleave the cohesin rings, leading to the separation of sister chromatids and the continuation of mitosis. If securin function is disrupted, it can lead to errors in chromosome segregation, which can contribute to genomic instability and diseases like 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.

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.

CDC20 proteins are a type of regulatory protein that play a crucial role in the cell cycle, which is the process by which cells grow and divide. Specifically, CDC20 proteins are involved in the transition from metaphase to anaphase during mitosis, the phase of the cell cycle where chromosomes are separated and distributed to two daughter cells.

CDC20 proteins function as part of a larger complex called the anaphase-promoting complex/cyclosome (APC/C), which targets specific proteins for degradation by the proteasome. During metaphase, CDC20 binds to the APC/C and helps to activate it, leading to the degradation of securin and cyclin B, two proteins that are essential for maintaining the proper attachment of chromosomes to the spindle apparatus.

Once these proteins are degraded, the sister chromatids can be separated and moved to opposite poles of the cell, allowing for the completion of mitosis and the formation of two genetically identical daughter cells. In addition to their role in mitosis, CDC20 proteins have also been implicated in other cellular processes, including meiosis, DNA damage repair, and apoptosis.

A centromere is a specialized region found on chromosomes that plays a crucial role in the separation of replicated chromosomes during cell division. It is the point where the sister chromatids (the two copies of a chromosome formed during DNA replication) are joined together. The centromere contains highly repeated DNA sequences and proteins that form a complex structure known as the kinetochore, which serves as an attachment site for microtubules of the mitotic spindle during cell division.

During mitosis or meiosis, the kinetochore facilitates the movement of chromosomes by interacting with the microtubules, allowing for the accurate distribution of genetic material to the daughter cells. Centromeres can vary in their position and structure among different species, ranging from being located near the middle of the chromosome (metacentric) to being positioned closer to one end (acrocentric). The precise location and characteristics of centromeres are essential for proper chromosome segregation and maintenance of genomic stability.

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.

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.

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.

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.

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.

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.

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).

Kinesin is not a medical term per se, but a term from the field of cellular biology. However, understanding how kinesins work is important in the context of medical and cellular research.

Kinesins are a family of motor proteins that play a crucial role in transporting various cargoes within cells, such as vesicles, organelles, and chromosomes. They move along microtubule filaments, using the energy derived from ATP hydrolysis to generate mechanical force and motion. This process is essential for several cellular functions, including intracellular transport, mitosis, and meiosis.

In a medical context, understanding kinesin function can provide insights into various diseases and conditions related to impaired intracellular transport, such as neurodegenerative disorders (e.g., Alzheimer's disease, Parkinson's disease, and Huntington's disease) and certain genetic disorders affecting motor neurons. Research on kinesins can potentially lead to the development of novel therapeutic strategies targeting these conditions.

Prophase is the first phase of mitosis, the process by which eukaryotic cells divide and reproduce. During prophase, the chromosomes condense and become visible. The nuclear envelope breaks down, allowing the spindle fibers to attach to the centromeres of each chromatid in the chromosome. This is a critical step in preparing for the separation of genetic material during cell division. Prophase is also marked by the movement of the centrosomes to opposite poles of the cell, forming the mitotic spindle.

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.

Cdh1 proteins are part of the anaphase-promoting complex/cyclosome (APC/C), which is a multi-subunit E3 ubiquitin ligase that plays a critical role in regulating the cell cycle. Cdh1, specifically, is a regulatory subunit of the APC/C and is essential for the proper progression through the cell cycle.

Cdh1 binds to and activates the APC/C in late mitosis and early G1 phase, targeting specific proteins for ubiquitination and subsequent degradation by the proteasome. This helps to ensure that key events of the cell cycle, such as chromosome segregation and mitotic exit, occur in a timely and orderly fashion.

Cdh1 has been shown to regulate the degradation of several important cell cycle regulators, including cyclins A and B, securin, and aurora kinase A. By targeting these proteins for destruction, Cdh1 helps to prevent premature entry into mitosis and ensures that cells do not exit mitosis until all chromosomes have been properly aligned and segregated.

Mutations in the genes encoding Cdh1 and other components of the APC/C have been implicated in a variety of human cancers, highlighting the importance of this complex in maintaining genomic stability.

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.

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.

Prometaphase is a stage in the cell division process called mitosis, where the nuclear membrane has broken down and the chromosomes are now moved into the center of the cell, also known as the metaphase plate. This movement is facilitated by the mitotic spindle, which attaches to specialized structures on the chromosomes called kinetochores. The prometaphase stage follows prophase and precedes metaphase in the mitosis process. It's characterized by the beginning of chromosome separation and the reorganization of the cell for the upcoming division into two daughter cells.

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.

Aurora Kinase B is a type of enzyme that plays a crucial role in the regulation of cell division and mitosis. It is a member of the Aurora kinase family, which includes three different isoforms (Aurora A, B, and C). Among these, Aurora Kinase B is specifically involved in the proper alignment and separation of chromosomes during cell division.

During mitosis, Aurora Kinase B forms a complex with other proteins to form the chromosomal passenger complex (CPC), which plays a critical role in ensuring accurate chromosome segregation. The CPC is responsible for regulating various events during mitosis, including the attachment of microtubules to kinetochores (protein structures that connect chromosomes to spindle fibers), the correction of erroneous kinetochore-microtubule attachments, and the regulation of the anaphase promoting complex/cyclosome (APC/C), which targets specific proteins for degradation during mitosis.

Dysregulation of Aurora Kinase B has been implicated in various human diseases, including cancer. Overexpression or amplification of this kinase can lead to chromosomal instability and aneuploidy, contributing to tumorigenesis and cancer progression. As a result, Aurora Kinase B is considered a promising target for the development of anti-cancer therapies, with several inhibitors currently being investigated in preclinical and clinical studies.

Spermatocytes are a type of cell that is involved in the process of spermatogenesis, which is the formation of sperm in the testes. Specifically, spermatocytes are the cells that undergo meiosis, a special type of cell division that results in the production of four haploid daughter cells, each containing half the number of chromosomes as the parent cell.

There are two types of spermatocytes: primary and secondary. Primary spermatocytes are diploid cells that contain 46 chromosomes (23 pairs). During meiosis I, these cells undergo a process called crossing over, in which genetic material is exchanged between homologous chromosomes. After crossing over, the primary spermatocytes divide into two secondary spermatocytes, each containing 23 chromosomes (but still with 23 pairs).

Secondary spermatocytes then undergo meiosis II, which results in the formation of four haploid spermatids. Each spermatid contains 23 single chromosomes and will eventually develop into a mature sperm cell through a process called spermiogenesis.

It's worth noting that spermatocytes are only found in males, as they are specific to the male reproductive system.

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.

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.

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.

"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.

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.

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.

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!

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.

Macropodidae is not a medical term, but a taxonomic family in the order Diprotodontia, which includes large marsupials commonly known as kangaroos, wallabies, and tree-kangaroos. These animals are native to Australia and New Guinea. They are characterized by their strong hind legs, large feet adapted for leaping, and a long muscular tail used for balance. Some members of this family, particularly the larger kangaroo species, can pose a risk to humans in certain situations, such as vehicle collisions or aggressive encounters during breeding season. However, they are not typically associated with medical conditions or human health.

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.

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.

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.

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.

APC2 (Anaphase-Promoting Complex Subunit 2) is a regulatory subunit of the multi-subunit E3 ubiquitin ligase complex known as the Anaphase-Promoting Complex/Cyclosome (APC/C). The APC/C plays a critical role in regulating cell division by targeting specific proteins for degradation via the ubiquitin-proteasome pathway.

The APC/C is responsible for marking proteins with ubiquitin molecules, which signals their recognition and destruction by the 26S proteasome. This process is essential for proper progression through the cell cycle, including the regulation of mitotic exit and the onset of anaphase during cell division.

APC2, along with APC1 (also known as CDC27), forms the core structural scaffold of the APC/C complex. The APC2 subunit is involved in binding both the ubiquitin-conjugating enzyme and the ubiquitin-protein ligase components of the complex, thereby facilitating the transfer of ubiquitin molecules to target proteins.

The activity of the APC/C is tightly regulated throughout the cell cycle by various cofactors that bind to and modulate its function. The binding of these cofactors determines the substrate specificity of the complex, allowing it to target different proteins at distinct stages of the cell cycle.

In summary, APC2 is a crucial subunit of the APC/C complex, which plays an essential role in regulating the cell cycle through targeted protein degradation via the ubiquitin-proteasome pathway.

Nondisjunction is a genetic term that refers to the failure of homologous chromosomes or sister chromatids to properly separate during cell division, resulting in an abnormal number of chromosomes in the daughter cells. This can occur during either mitosis (resulting in somatic mutations) or meiosis (leading to gametes with an incorrect number of chromosomes).

In humans, nondisjunction of chromosome 21 during meiosis is the most common cause of Down syndrome, resulting in three copies of chromosome 21 (trisomy 21) in the affected individual. Nondisjunction can also result in other aneuploidies, such as Turner syndrome (X monosomy), Klinefelter syndrome (XXY), and Edwards syndrome (trisomy 18).

Nondisjunction is typically a random event, although maternal age has been identified as a risk factor for nondisjunction during meiosis. In some cases, structural chromosomal abnormalities or genetic factors may predispose an individual to nondisjunction events.

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.

Chromosomes in fungi are thread-like structures that contain genetic material, composed of DNA and proteins, present in the nucleus of a cell. Unlike humans and other eukaryotes that have a diploid number of chromosomes in their somatic cells, fungal chromosome numbers can vary widely between and within species.

Fungal chromosomes are typically smaller and fewer in number compared to those found in plants and animals. The chromosomal organization in fungi is also different from other eukaryotes. In many fungi, the chromosomes are condensed throughout the cell cycle, whereas in other eukaryotes, chromosomes are only condensed during cell division.

Fungi can have linear or circular chromosomes, depending on the species. For example, the model organism Saccharomyces cerevisiae (budding yeast) has a set of 16 small circular chromosomes, while other fungi like Neurospora crassa (red bread mold) and Aspergillus nidulans (a filamentous fungus) have linear chromosomes.

Fungal chromosomes play an essential role in the growth, development, reproduction, and survival of fungi. They carry genetic information that determines various traits such as morphology, metabolism, pathogenicity, and resistance to environmental stresses. Advances in genomic technologies have facilitated the study of fungal chromosomes, leading to a better understanding of their structure, function, and evolution.

Chromosomes are thread-like structures that contain genetic material, i.e., DNA and proteins, present in the nucleus of human cells. In humans, there are 23 pairs of chromosomes, for a total of 46 chromosomes, in each diploid cell. Twenty-two of these pairs are called autosomal chromosomes, which come in identical pairs and contain genes that determine various traits unrelated to sex.

The last pair is referred to as the sex chromosomes (X and Y), which determines a person's biological sex. Females have two X chromosomes (46, XX), while males possess one X and one Y chromosome (46, XY). Chromosomes vary in size, with the largest being chromosome 1 and the smallest being the Y chromosome.

Human chromosomes are typically visualized during mitosis or meiosis using staining techniques that highlight their banding patterns, allowing for identification of specific regions and genes. Chromosomal abnormalities can lead to various genetic disorders, including Down syndrome (trisomy 21), Turner syndrome (monosomy X), and Klinefelter syndrome (XXY).

Dyneins are a type of motor protein that play an essential role in the movement of cellular components and structures within eukaryotic cells. They are responsible for generating force and motion along microtubules, which are critical components of the cell's cytoskeleton. Dyneins are involved in various cellular processes, including intracellular transport, organelle positioning, and cell division.

There are several types of dyneins, but the two main categories are cytoplasmic dyneins and axonemal dyneins. Cytoplasmic dyneins are responsible for moving various cargoes, such as vesicles, organelles, and mRNA complexes, toward the minus-end of microtubules, which is usually located near the cell center. Axonemal dyneins, on the other hand, are found in cilia and flagella and are responsible for their movement by sliding adjacent microtubules past each other.

Dyneins consist of multiple subunits, including heavy chains, intermediate chains, light-intermediate chains, and light chains. The heavy chains contain the motor domain that binds to microtubules and hydrolyzes ATP to generate force. Dysfunction in dynein proteins has been linked to various human diseases, such as neurodevelopmental disorders, ciliopathies, and cancer.

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.

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.

APC8 (Anaphase-Promoting Complex-Cyclosome) subunit, also known as APC5 or CDC27, is a crucial component of the anaphase-promoting complex/cyclosome (APC/C), which is a multi-subunit E3 ubiquitin ligase that plays a critical role in regulating the cell cycle. Specifically, APC8 is one of the essential subunits that make up the core structure of the APC/C and is involved in its recognition and binding to specific substrates.

APC/C targets various proteins for ubiquitination and subsequent degradation by the 26S proteasome, thereby controlling different stages of mitosis and meiosis. During anaphase, APC/C-mediated degradation of securin and cyclin B leads to sister chromatid separation and exit from mitosis.

APC8 is a highly conserved protein found in many eukaryotes, including yeast, flies, and humans. Mutations in the gene encoding APC8 have been associated with various human diseases, such as cancer and developmental disorders.

Endopeptidases are a type of enzyme that breaks down proteins by cleaving peptide bonds inside the polypeptide chain. They are also known as proteinases or endoproteinases. These enzymes work within the interior of the protein molecule, cutting it at specific points along its length, as opposed to exopeptidases, which remove individual amino acids from the ends of the protein chain.

Endopeptidases play a crucial role in various biological processes, such as digestion, blood coagulation, and programmed cell death (apoptosis). They are classified based on their catalytic mechanism and the structure of their active site. Some examples of endopeptidase families include serine proteases, cysteine proteases, aspartic proteases, and metalloproteases.

It is important to note that while endopeptidases are essential for normal physiological functions, they can also contribute to disease processes when their activity is unregulated or misdirected. For instance, excessive endopeptidase activity has been implicated in the pathogenesis of neurodegenerative disorders, cancer, and inflammatory conditions.

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.

I'm sorry for any confusion, but "Potoroidae" is not a medical term. It is a taxonomic family within the order Diprotodontia, which includes several species of rat-kangaroos that are native to Australia. These small marsupials are known for their hopping locomotion and nocturnal behavior. If you have any questions about veterinary or medical terminology, I would be happy to help with those!

Catenated DNA refers to the linking or interlocking of two or more DNA molecules in a circular form, where the circles are topologically entangled. This occurs during DNA replication when the sister chromatids (identical copies of DNA) are formed and remain interlinked before they are separated during cell division. The term "catenane" is used to describe this interlocking structure. It is important to note that in linear DNA, the term "catenated" does not apply since there is no circular formation.

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.

'Dipodomys' is the genus name for kangaroo rats, which are small rodents native to North America. They are called kangaroo rats due to their powerful hind legs and long tails, which they use to hop around like kangaroos. Kangaroo rats are known for their ability to survive in arid environments, as they are able to obtain moisture from the seeds they eat and can concentrate their urine to conserve water. They are also famous for their highly specialized kidneys, which allow them to produce extremely dry urine.

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.

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.

Sister chromatid exchange (SCE) is a type of genetic recombination that takes place between two identical sister chromatids during the DNA repair process in meiosis or mitosis. It results in an exchange of genetic material between the two chromatids, creating a new combination of genes on each chromatid. This event is a normal part of cell division and helps to increase genetic variability within a population. However, an increased rate of SCEs can also be indicative of exposure to certain genotoxic agents or conditions that cause DNA damage.

Protein Tyrosine Phosphatases (PTPs) are a group of enzymes that play a crucial role in the regulation of various cellular processes, including cell growth, differentiation, and signal transduction. PTPs function by removing phosphate groups from tyrosine residues on proteins, thereby counteracting the effects of tyrosine kinases, which add phosphate groups to tyrosine residues to activate proteins.

PTPs are classified into several subfamilies based on their structure and function, including classical PTPs, dual-specificity PTPs (DSPs), and low molecular weight PTPs (LMW-PTPs). Each subfamily has distinct substrate specificities and regulatory mechanisms.

Classical PTPs are further divided into receptor-like PTPs (RPTPs) and non-receptor PTPs (NRPTPs). RPTPs contain a transmembrane domain and extracellular regions that mediate cell-cell interactions, while NRPTPs are soluble enzymes located in the cytoplasm.

DSPs can dephosphorylate both tyrosine and serine/threonine residues on proteins and play a critical role in regulating various signaling pathways, including the mitogen-activated protein kinase (MAPK) pathway.

LMW-PTPs are a group of small molecular weight PTPs that localize to different cellular compartments, such as the endoplasmic reticulum and mitochondria, and regulate various cellular processes, including protein folding and apoptosis.

Overall, PTPs play a critical role in maintaining the balance of phosphorylation and dephosphorylation events in cells, and dysregulation of PTP activity has been implicated in various diseases, including cancer, diabetes, and neurological disorders.

Aneuploidy is a medical term that refers to an abnormal number of chromosomes in a cell. Chromosomes are thread-like structures located inside the nucleus of cells that contain genetic information in the form of genes.

In humans, the normal number of chromosomes in a cell is 46, arranged in 23 pairs. Aneuploidy occurs when there is an extra or missing chromosome in one or more of these pairs. For example, Down syndrome is a condition that results from an extra copy of chromosome 21, also known as trisomy 21.

Aneuploidy can arise during the formation of gametes (sperm or egg cells) due to errors in the process of cell division called meiosis. These errors can result in eggs or sperm with an abnormal number of chromosomes, which can then lead to aneuploidy in the resulting embryo.

Aneuploidy is a significant cause of birth defects and miscarriages. The severity of the condition depends on which chromosomes are affected and the extent of the abnormality. In some cases, aneuploidy may have no noticeable effects, while in others it can lead to serious health problems or developmental delays.

Diptera is an order of insects that includes flies, mosquitoes, and gnats. The name "Diptera" comes from the Greek words "di," meaning two, and "pteron," meaning wing. This refers to the fact that all members of this order have a single pair of functional wings for flying, while the other pair is reduced to small knob-like structures called halteres, which help with balance and maneuverability during flight.

Some common examples of Diptera include houseflies, fruit flies, horseflies, tsetse flies, and midges. Many species in this order are important pollinators, while others can be significant pests or disease vectors. The study of Diptera is called dipterology.

'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.

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.

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.

Chromosomal instability is a term used in genetics to describe a type of genetic alteration where there are abnormalities in the number or structure of chromosomes within cells. Chromosomes are thread-like structures that contain our genetic material, and they usually exist in pairs in the nucleus of a cell.

Chromosomal instability can arise due to various factors, including errors in DNA replication or repair, problems during cell division, or exposure to environmental mutagens. This instability can lead to an increased frequency of chromosomal abnormalities, such as deletions, duplications, translocations, or changes in the number of chromosomes.

Chromosomal instability is associated with several human diseases, including cancer. In cancer cells, chromosomal instability can contribute to tumor heterogeneity, drug resistance, and disease progression. It is also observed in certain genetic disorders, such as Down syndrome, where an extra copy of chromosome 21 is present, and in some rare inherited syndromes, such as Bloom syndrome and Fanconi anemia, which are characterized by a high risk of cancer and other health problems.

Video microscopy is a medical technique that involves the use of a microscope equipped with a video camera to capture and display real-time images of specimens on a monitor. This allows for the observation and documentation of dynamic processes, such as cell movement or chemical reactions, at a level of detail that would be difficult or impossible to achieve with the naked eye. Video microscopy can also be used in conjunction with image analysis software to measure various parameters, such as size, shape, and motion, of individual cells or structures within the specimen.

There are several types of video microscopy, including brightfield, darkfield, phase contrast, fluorescence, and differential interference contrast (DIC) microscopy. Each type uses different optical techniques to enhance contrast and reveal specific features of the specimen. For example, fluorescence microscopy uses fluorescent dyes or proteins to label specific structures within the specimen, allowing them to be visualized against a dark background.

Video microscopy is used in various fields of medicine, including pathology, microbiology, and neuroscience. It can help researchers and clinicians diagnose diseases, study disease mechanisms, develop new therapies, and understand fundamental biological processes at the cellular and molecular level.

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.

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 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

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.

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.

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.

Salamandridae is not a medical term, but a taxonomic designation in the field of biology. It refers to a family of amphibians commonly known as newts and salamanders. These creatures are characterized by their slender bodies, moist skin, and four legs. Some species have the ability to regenerate lost body parts, including limbs, spinal cord, heart, and more.

If you're looking for a medical term, please provide more context or check if you may have made a typo in your question.

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.

Nuclear matrix-associated proteins (NMAPs) are a group of structural and functional proteins that are associated with the nuclear matrix, a network of fibers within the nucleus of a eukaryotic cell. The nuclear matrix provides support to the nuclear envelope and plays a role in DNA replication, transcription, and repair. NMAPs can be categorized into several groups based on their functions, including:

1. Scaffold proteins: These proteins provide structural support to the nuclear matrix and help maintain its architecture.
2. Enzymes: These proteins are involved in various biochemical reactions, such as DNA replication and repair, RNA processing, and chromatin remodeling.
3. Transcription factors: These proteins regulate gene expression by binding to specific DNA sequences and interacting with the transcription machinery.
4. Chromatin-associated proteins: These proteins are involved in the organization and regulation of chromatin structure and function.
5. Signal transduction proteins: These proteins transmit signals from the extracellular environment to the nucleus, regulating gene expression and other nuclear functions.

NMAPs have been implicated in various cellular processes, including cell cycle regulation, differentiation, apoptosis, and oncogenesis. Therefore, understanding the structure and function of NMAPs is crucial for elucidating the mechanisms underlying these processes and developing novel therapeutic strategies for various diseases, including cancer.

Calcium-binding proteins (CaBPs) are a diverse group of proteins that have the ability to bind calcium ions (Ca^2+^) with high affinity and specificity. They play crucial roles in various cellular processes, including signal transduction, muscle contraction, neurotransmitter release, and protection against oxidative stress.

The binding of calcium ions to these proteins induces conformational changes that can either activate or inhibit their functions. Some well-known CaBPs include calmodulin, troponin C, S100 proteins, and parvalbumins. These proteins are essential for maintaining calcium homeostasis within cells and for mediating the effects of calcium as a second messenger in various cellular signaling pathways.

Micromanipulation is a term used in the field of medicine, specifically in assisted reproductive technologies (ARTs) such as in vitro fertilization (IVF). It refers to a technique that involves the manipulation of oocytes (human eggs), sperm, and/or embryos under a microscope using micromanipulative tools and equipment.

The most common form of micromanipulation is intracytoplasmic sperm injection (ICSI), where a single sperm is selected and injected directly into the cytoplasm of an oocyte to facilitate fertilization. Other forms of micromanipulation include assisted hatching (AH), where a small opening is made in the zona pellucida (the protective layer surrounding the embryo) to help the embryo hatch and implant into the uterus, and embryo biopsy, which involves removing one or more cells from an embryo for genetic testing.

Micromanipulation requires specialized training and equipment and is typically performed in IVF laboratories by experienced embryologists. The goal of micromanipulation is to improve the chances of successful fertilization, implantation, and pregnancy, particularly in cases where conventional methods have been unsuccessful or when there are specific fertility issues, such as male factor infertility or genetic disorders.

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.

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.

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.

Microinjection is a medical technique that involves the use of a fine, precise needle to inject small amounts of liquid or chemicals into microscopic structures, cells, or tissues. This procedure is often used in research settings to introduce specific substances into individual cells for study purposes, such as introducing DNA or RNA into cell nuclei to manipulate gene expression.

In clinical settings, microinjections may be used in various medical and cosmetic procedures, including:

1. Intracytoplasmic Sperm Injection (ICSI): A type of assisted reproductive technology where a single sperm is injected directly into an egg to increase the chances of fertilization during in vitro fertilization (IVF) treatments.
2. Botulinum Toxin Injections: Microinjections of botulinum toxin (Botox, Dysport, or Xeomin) are used for cosmetic purposes to reduce wrinkles and fine lines by temporarily paralyzing the muscles responsible for their formation. They can also be used medically to treat various neuromuscular disorders, such as migraines, muscle spasticity, and excessive sweating (hyperhidrosis).
3. Drug Delivery: Microinjections may be used to deliver drugs directly into specific tissues or organs, bypassing the systemic circulation and potentially reducing side effects. This technique can be particularly useful in treating localized pain, delivering growth factors for tissue regeneration, or administering chemotherapy agents directly into tumors.
4. Gene Therapy: Microinjections of genetic material (DNA or RNA) can be used to introduce therapeutic genes into cells to treat various genetic disorders or diseases, such as cystic fibrosis, hemophilia, or cancer.

Overall, microinjection is a highly specialized and precise technique that allows for the targeted delivery of substances into small structures, cells, or tissues, with potential applications in research, medical diagnostics, and therapeutic interventions.

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.

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.

Benomyl is a systemic fungicide that is derived from methyl 1-(butylcarbamoyl)-2-benzimidazole carbamate. It works by inhibiting the synthesis of microtubules in fungal cells, which are necessary for cell division and growth. Benomyl is used to control a wide range of fungal diseases in crops such as cereals, fruits, vegetables, and ornamental plants. However, it has been banned or restricted in many countries due to its potential toxicity to non-target organisms, including humans.

In medical contexts, benomyl is not used as a drug or therapy. It can be harmful if ingested, inhaled, or comes into contact with the skin, and may cause symptoms such as nausea, vomiting, diarrhea, abdominal pain, dizziness, headache, and respiratory difficulties. Long-term exposure to benomyl has been linked to neurological and reproductive effects in animals, but its effects on human health are not well understood.

Luminescent proteins are a type of protein that emit light through a chemical reaction, rather than by absorbing and re-emitting light like fluorescent proteins. This process is called bioluminescence. The light emitted by luminescent proteins is often used in scientific research as a way to visualize and track biological processes within cells and organisms.

One of the most well-known luminescent proteins is Green Fluorescent Protein (GFP), which was originally isolated from jellyfish. However, GFP is actually a fluorescent protein, not a luminescent one. A true example of a luminescent protein is the enzyme luciferase, which is found in fireflies and other bioluminescent organisms. When luciferase reacts with its substrate, luciferin, it produces light through a process called oxidation.

Luminescent proteins have many applications in research, including as reporters for gene expression, as markers for protein-protein interactions, and as tools for studying the dynamics of cellular processes. They are also used in medical imaging and diagnostics, as well as in the development of new therapies.

Kymography is a medical imaging technique used to visualize and analyze the movement or motion of structures, such as muscles, blood vessels, or intestines, over time. It involves capturing a series of images at high temporal resolution and then displaying them in a way that emphasizes changes in intensity along a single line or region of interest.

In kymography, a moving stripe or band is created on the image display, representing the movement of the structure being studied. The resulting image shows the velocity, direction, and patterns of motion of the structure, which can be useful for diagnostic purposes or for research in physiology and biomechanics.

Kymography is often used in conjunction with other imaging techniques, such as ultrasound or fluoroscopy, to provide more detailed information about the function and behavior of different tissues and organs.

"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.

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.

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.

The nuclear envelope is a complex and double-membrane structure that surrounds the eukaryotic cell's nucleus. It consists of two distinct membranes: the outer nuclear membrane, which is continuous with the endoplasmic reticulum (ER) membrane, and the inner nuclear membrane, which is closely associated with the chromatin and nuclear lamina.

The nuclear envelope serves as a selective barrier between the nucleus and the cytoplasm, controlling the exchange of materials and information between these two cellular compartments. Nuclear pore complexes (NPCs) are embedded in the nuclear envelope at sites where the inner and outer membranes fuse, forming aqueous channels that allow for the passive or active transport of molecules, such as ions, metabolites, and RNA-protein complexes.

The nuclear envelope plays essential roles in various cellular processes, including DNA replication, transcription, RNA processing, and chromosome organization. Additionally, it is dynamically regulated during the cell cycle, undergoing disassembly and reformation during mitosis to facilitate equal distribution of genetic material between daughter cells.

Demecolcine is a medication that belongs to the class of drugs called anticholinergics. It is derived from the plant alkaloid colchicine and has been used in medical research for its ability to arrest cells in metaphase, a specific stage of cell division. This property makes demecolcine useful in various laboratory procedures such as chromosome analysis and the production of cultured cell lines.

In clinical settings, demecolcine is not commonly used due to its narrow therapeutic index and potential for toxicity. However, it has been used off-label in some cases to treat conditions associated with uncontrolled cell division, such as certain types of cancer. Its use in these situations is typically reserved for when other treatments have failed or are not well tolerated.

It's important to note that demecolcine should only be administered under the close supervision of a healthcare professional and its use is generally avoided in pregnant women due to the risk of fetal harm.

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.

I'm sorry for any confusion, but "grasshoppers" is not a term used in medical definitions. Grasshoppers are a type of insect that belongs to the order Orthoptera and suborder Caelifera. They are known for their long hind legs which they use for jumping, and some species can jump over 20 times their own body length. If you have any questions about medical terminology or topics, I'd be happy to help with those instead!

Chromosome positioning, also known as chromosome organization or chromosome architecture, refers to the specific location and spatial arrangement of chromosomes within the nucleus of a eukaryotic cell. This complex process is critical for proper regulation of gene expression, DNA replication, and chromosomal stability during the cell cycle.

Chromosomes are not randomly positioned in the nucleus; instead, they occupy distinct territories that are non-randomly organized with respect to each other. Chromosome positioning is influenced by several factors, including the presence of nuclear bodies, such as the nucleolus and nuclear speckles, as well as by the interactions between chromatin regions and the nuclear lamina.

The spatial organization of chromosomes can have significant consequences for gene regulation, as genes that are located in close proximity to each other may be more likely to interact and influence each other's expression. Chromosome positioning has also been implicated in various diseases, including cancer, where abnormalities in chromosome organization have been associated with changes in gene expression and genomic instability.

Overall, the medical definition of 'chromosome positioning' refers to the complex and dynamic process by which chromosomes are organized within the nucleus of a cell, and how this organization influences various cellular processes and functions.

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.

APC1 (Anaphase-Promoting Complex-Cyclosome) subunit is a component of the multi-subunit E3 ubiquitin ligase complex known as the Anaphase-Promoting Complex/Cyclosome (APC/C). The APC/C plays a crucial role in regulating the cell cycle, specifically during mitosis and meiosis.

The APC/C is responsible for targeting specific proteins for degradation by the ubiquitin-proteasome system. This degradation leads to the regulation of various cell cycle events, such as sister chromatid separation during anaphase and the exit from mitosis.

APC1 is one of the several subunits that make up the APC/C complex. It serves as a scaffold protein, helping to assemble and maintain the structural integrity of the complex. Additionally, APC1 has been shown to play a role in substrate recognition by the APC/C, contributing to the specificity of ubiquitination and subsequent degradation of target proteins.

The medical relevance of understanding the APC/C and its subunits, including APC1, lies in their essential roles in cell cycle regulation. Dysregulation of these processes can lead to various diseases, such as cancer, where uncontrolled cell division is a hallmark feature. Studying the APC/C and its components may provide insights into potential therapeutic targets for treating such conditions.

... is characterized by two distinct motions. The first of these, anaphase A, moves chromosomes to either pole of a ... Anaphase starts when the anaphase promoting complex marks an inhibitory chaperone called securin for destruction by ... Interphase Prophase Prometaphase Metaphase Telophase Cytoskeleton Anaphase I Anaphase II Cdc20 "Chromosome condensation through ... The second motion, anaphase B, involves the separation of these poles from each other. The movement for this is primarily ...
In either case, anaphase lag will cause one daughter cell to receive a complete set of chromosomes while the other lacks one ... Anaphase lag is a consequence of an event during cell division where sister chromatids do not properly separate from each other ... The chromosome or chromatid does not properly migrate during anaphase and the daughter cells will lose some genetic information ... There are two notable mechanisms that cause Anaphase Lag, each of which are characterized by merotelic attachments of ...
i.e.: The subunit, CDC20 allows APC to degrade substrates such as anaphase inhibitors (Pdsp1) at the beginning of anaphase, on ... Anaphase-promoting complex (also called the cyclosome or APC/C) is an E3 ubiquitin ligase that marks target cell cycle proteins ... anaphase-promoting+complex at the U.S. National Library of Medicine Medical Subject Headings (MeSH) 3D electron microscopy ... The molecular basis of the delay is unknown, but is believed to involve the key to the correct timing of anaphase initiation. ...
Anaphase lag occurs when the movement of one chromatid is impeded during anaphase. This may be caused by a failure of the ... During anaphase B, polar microtubules push against each other, causing the cell to elongate. In late anaphase, chromosomes also ... In most animal cells, anaphase A precedes anaphase B, but some vertebrate egg cells demonstrate the opposite order of events. ... If the cell successfully passes through the metaphase checkpoint, it proceeds to anaphase. During anaphase A, the cohesins that ...
Rhoades, M.M.; Vilkomerson (1942). "On the anaphase movement of chromosomes". Proc. Natl. Acad. Sci. 28 (10): 433-436. Bibcode: ...
Rhoades, M. M.; Vilkomerson, H. (1942-10-01). "On the Anaphase Movement of Chromosomes". Proceedings of the National Academy of ...
In the anaphase of mitosis, sister chromatids separate and migrate to opposite cell poles before the cell divides. ... During anaphase, cohesin is cleaved by separase. Topoisomerase II and condensin are responsible for removing catenations. The ... This is known as a chromatin bridge or an anaphase bridge. Mitotic nondisjunction results in somatic mosaicism, since only ... Only then, SAC releases its inhibition of the anaphase promoting complex (APC), which in turn irreversibly triggers progression ...
The anaphase-mediated distancing of chromosomes from the metaphase plate may trigger spatial cues for the onset of telophase. ... Experimental addition of non-degradable M-cyclin to cells induces cell cycle arrest in a post-anaphase/pre-telophase-like state ... Historically, it has been thought that anaphase and telophase are events that occur passively after satisfaction of the spindle ... The Cdc-14 Early Anaphase Release pathway, which stabilizes the spindle, also releases cdc14 from the nucleolus but restricts ...
Smc3 remains acetylated until at least anaphase. Once cohesin has been removed from the chromatin, Smc3 is deacetylated by Hos1 ...
... which is tightly bound by the anaphase inhibitor Pds1 that is destroyed by the anaphase-promoting complex. In order to verify ... In this theory, anaphase promoting complex (APC), a class of ubiquitin ligase, facilitates degradation of mitotic cyclins (Clb2 ... FEAR (Cdc14 early anaphase release) pathway facilitates Clb2-Cdk1-dependent phosphorylation of Net1 which transiently releases ... Once cells are in mitosis, cyclin B-Cdk1 activates the anaphase-promoting complex (APC), which in turn inactivates cyclin B- ...
Zhai Y, Kronebusch PJ, Borisy GG (November 1995). "Kinetochore microtubule dynamics and the metaphase-anaphase transition". The ...
Without Cdc20, the anaphase-promoting complex (APC) cannot become activated and anaphase is not triggered. Mad2 was shown to ... Entrance into anaphase is mediated by APCCdc20 activation. APCCdc20 is a ubiquitin-protein ligase that tags the protein, ... It is speculated that once formed, Cdc20:Mad2 complexes can amplify the anaphase wait signal by stimulating further conversion ... The spindle checkpoint system is a regulatory system that restrains progression through the metaphase-to-anaphase transition. ...
Anaphase-promoting complex subunit 7 is an enzyme that in humans is encoded by the ANAPC7 gene. Multiple transcript variants ... "Entrez Gene: ANAPC7 anaphase promoting complex subunit 7". Vodermaier HC, Gieffers C, Maurer-Stroh S, Eisenhaber F, Peters JM ( ... Park KH, Choi SE, Eom M, Kang Y (2006). "Downregulation of the anaphase-promoting complex (APC)7 in invasive ductal carcinomas ... 2000). "The RING-H2 finger protein APC11 and the E2 enzyme UBC4 are sufficient to ubiquitinate substrates of the anaphase- ...
Because this event is most prevalent during anaphase, the term anaphase bridge is often used as a substitute. After the ... Hoffelder D, Luo L, Burke N, Watkins S, Gollin S, Saunders W (2004). "Resolution of anaphase bridges in cancer cells" (PDF). ... Chan KL, Hickson ID (2011). "New insights into the formation and resolution of ultra-fine anaphase bridges". Semin Cell Dev ... Kok Lung Chan (October 2011). "New insights into the formation and resolution of ultra-fine anaphase bridges". Seminars in Cell ...
A large protein complex, termed the anaphase-promoting complex (APC), or the cyclosome, promotes metaphase-anaphase transition ... Anaphase-promoting complex subunit 4 is an enzyme that in humans is encoded by the ANAPC4 gene. ... "Entrez Gene: ANAPC4 anaphase promoting complex subunit 4". Vodermaier, Hartmut C; Gieffers, Christian; Maurer-Stroh, Sebastian ... 2000). "The RING-H2 finger protein APC11 and the E2 enzyme UBC4 are sufficient to ubiquitinate substrates of the anaphase- ...
During Anaphase, both recombinants are faced with problems. The acentric chromatid is pulled to one pole or the other, and the ...
Anaphase-promoting complex subunit 10 is an enzyme that in humans is encoded by the ANAPC10 gene. ANAPC10 has been shown to ... "Entrez Gene: ANAPC10 anaphase promoting complex subunit 10". Vodermaier HC, Gieffers C, Maurer-Stroh S, Eisenhaber F, Peters JM ... Vodermaier HC, Gieffers C, Maurer-Stroh S, Eisenhaber F, Peters JM (September 2003). "TPR subunits of the anaphase-promoting ... Kurasawa Y, Todokoro K (September 1999). "Identification of human APC10/Doc1 as a subunit of anaphase promoting complex". ...
Anaphase-promoting complex subunit 5 is an enzyme that in humans is encoded by the ANAPC5 gene. The anaphase-promoting complex ... "Entrez Gene: ANAPC5 anaphase promoting complex subunit 5". Vodermaier, Hartmut C; Gieffers, Christian; Maurer-Stroh, Sebastian ... 2000). "The RING-H2 finger protein APC11 and the E2 enzyme UBC4 are sufficient to ubiquitinate substrates of the anaphase- ... 1999). "Characterization of the DOC1/APC10 subunit of the yeast and the human anaphase-promoting complex". J. Biol. Chem. 274 ( ...
Hair follicles in anaphase express four different caspases. Significant levels of inflammatory infiltrate have been found in ...
... is one of at least ten subunits of the anaphase-promoting complex (APC), which functions at the metaphase-to-anaphase ... Anaphase-promoting complex subunit 1 is an enzyme that in humans is encoded by the ANAPC1 gene. ... "Entrez Gene: ANAPC1 anaphase promoting complex subunit 1". Vodermaier, Hartmut C; Gieffers, Christian; Maurer-Stroh, Sebastian ... 2000). "The RING-H2 finger protein APC11 and the E2 enzyme UBC4 are sufficient to ubiquitinate substrates of the anaphase- ...
During anaphase, Cdc14 is "uncaged" and spreads to the rest of the cell. Two networks mediate the release of Cdc14 from the ... Cdh1 associates with the APC and leads to APC activity (anaphase promoting complex); activated APC is a key driver in mitotic ... FEAR (Cdc Fourteen Early Anaphase Release) complex proteins, SLK19 and SPO12 regulate the release of Cdc14. The release of ... The abnormality arises due to delay in dissembling of spindle during Anaphase I. However, the segregation of chromosomes ...
The chromosomes move to opposite poles during anaphase and remain attached to the spindle fibers by their centromeres. Animal ... Mitosis includes four phases: prophase, metaphase, anaphase, and telophase. Prophase is the initial phase when spindle fibers ... which forms during early anaphase. Myosin is present in the region of the contractile ring as concentrated microfilaments and ...
The site of cell division is determined before anaphase. The anaphase spindle (in green on the figure) is then positioned so ...
Prophase Prometaphase Metaphase Anaphase Telophase Cytoskeleton Marieb E (2000). Essentials of human anatomy and physiology. ...
20 July - The anaphase-promoting complex - one of the most important and complicated proteins involved in cell division - has ... "Molecular architecture and mechanism of the anaphase-promoting complex". Nature. 513 (7518): 388-393. Bibcode:2014Natur.513.. ...
The chromatids separate and the nuclei elongate in anaphase. This is followed by an increase in vesicles on the inner membrane ...
... is a component of the mitotic spindle assembly checkpoint that prevents the onset of anaphase until all chromosomes are ... Chen J, Fang G (2001). "MAD2B is an inhibitor of the anaphase-promoting complex". Genes Dev. 15 (14): 1765-1770. doi:10.1101/ ...
... also functions in resolving Sister chromatids prior to Anaphase. SMC2 has been shown to interact with DNMT3B. Mutations in ...
She performed in vitro biochemical characterisation of the activity of the anaphase-promoting complex (APC) and used cryo-EM to ... Passmore, Lori Anne (2003). Structural and functional studies of the anaphase promoting complex (APC). london.ac.uk (PhD thesis ... "Doc1 mediates the activity of the anaphase-promoting complex by contributing to substrate recognition". The EMBO Journal. 22 (4 ... "Structural analysis of the anaphase-promoting complex reveals multiple active sites and insights into polyubiquitylation". ...
Its targets include regulators of Ras, CDK2, and Cyclin A. USP44 plays an important role in anaphase initiation. New research ... One of the core regulator proteins is the anaphase-promoting complex (APC/C). APC/C ubiquitinates securin. The resulting ... April 2007). "Anaphase initiation is regulated by antagonistic ubiquitination and deubiquitination activities". Nature. 446 ( ... January 2004). "Loss of the anaphase-promoting complex in quiescent cells causes unscheduled hepatocyte proliferation". Genes ...
Anaphase is characterized by two distinct motions. The first of these, anaphase A, moves chromosomes to either pole of a ... Anaphase starts when the anaphase promoting complex marks an inhibitory chaperone called securin for destruction by ... Interphase Prophase Prometaphase Metaphase Telophase Cytoskeleton Anaphase I Anaphase II Cdc20 "Chromosome condensation through ... The second motion, anaphase B, involves the separation of these poles from each other. The movement for this is primarily ...
HeLa cell in anaphase. The chromosomes are stained blue and the microtubules forming the spindle are stained green. The pink ... HeLa cell in anaphase. The chromosomes are stained blue and the microtubules forming the spindle are stained green. The pink ... Human cell in anaphase. .. Matthew Daniels. . Attribution 4.0 International (CC BY 4.0). . Source: Wellcome Collection. ...
View mouse Anapc1 Chr2:128452024-128529311 with: phenotypes, sequences, polymorphisms, proteins, references, function, expression
Cell in anaphase.. Image courtesy of Wikimedia Commons and Roy van Heesbeen. ...
Protein target information for Anaphase-promoting complex subunit 2 (zebrafish). Find diseases associated with this biological ...
... producing a delay at the metaphase-anaphase transition until the last spindle attachment is made. Complete loss of the mitotic ... MAD2 haplo-insuffciency causes premature anaphase and chromosome instability in mammalian cells. Michel, Loren S.; Liberal, ... producing a delay at the metaphase-anaphase transition until the last spindle attachment is made. Complete loss of the mitotic ...
Different Phosphorylation States of the Anaphase Promoting Complex in Response to Anti-Mitotic Drugs: A Quantitative Proteomic ... Different Phosphorylation States of the Anaphase Promoting Complex in Response to Anti-Mitotic Drugs: A Quantitative Proteomic ...
The anaphase-promoting complex/cyclosome (APC/C) is a multisubunit ubiquitin ligase that regulates progression through the cell ... article{2042270, abstract = {{The anaphase-promoting complex/cyclosome (APC/C) is a multisubunit ubiquitin ligase that ... Arabidopsis ULTRAVIOLET-B-INSENSITIVE4 maintains cell division activity by temporal inhibition of the anaphase-promoting ... "Arabidopsis ULTRAVIOLET-B-INSENSITIVE4 Maintains Cell Division Activity by Temporal Inhibition of the Anaphase-Promoting ...
... resulting in diffuse localisation of the protein during anaphase, whereas TumΔYRL protein reaches the cell equator at anaphase ... At anaphase AurB moves to the central spindle and cortex in wild-type cells (arrow, A) but is not localised correctly in mutant ... At anaphase AurB moves to the central spindle and cortex in wild-type cells (arrow, A) but is not localised correctly in mutant ... Anaphase microtubule reorganization fails in tum mutant cells. (A-D) Tum localisation in wild-type dividing cells. DNA (A and ...
In this paper, we present evidence that anaphase B is induced by the minus end-stabilizing protein patronin, which antagonizes ... Anaphase B spindle elongation contributes to chromosome segregation during Drosophila melanogaster embryo mitosis. We propose ... Anaphase B spindle elongation contributes to chromosome segregation during Drosophila melanogaster embryo mitosis. We propose ... In this paper, we present evidence that anaphase B is induced by the minus end-stabilizing protein patronin, which antagonizes ...
This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are as essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may have an effect on your browsing experience ...
Anaphase is my favorite of these limericks...both touching and accurate from a cell biology standpoint. ... So what do we call these structures once the centromere separates at anaphase? Ive seen a few textbooks that say the ... The definitions get a bit tricky during anaphase (and telophase). During metaphase each chromosome is a pair of sisters held ... chromosome number in the cell doubles in anaphase (i.e. a human cell has 46 chromosomes in metaphase and 92 in anaphase)...but ...
Be the first to review "Ducray Anaphase Shampoo" Cancel reply. Your email address will not be published. Required fields are ...
The onset of anaphase is triggered by activation of the anaphase promoting complex/cyclosome (APC/C), following silencing of ... 2017) Identification of a Sgo2-dependent but Mad2-independent pathway controlling anaphase onset in fission yeast. Cell Reports ... Identification of a Sgo2-dependent but Mad2-independent pathway controlling anaphase onset in fission yeast ...
This stimulating cream shampoo is the perfect complement to anti-hair loss treatments. It restores volume, strength and vigor to your hair and can be used as often as necessary.Results: Stronger, more resistant hair 88% Pleasant fragrance for 95% of users Easy application: 90% 400 ml
Posted in meet the businessTagged anaphase store, business, cardiff, Clothes, Ecommerce, meet the business, online shop, Wales ... MT: What are the new plans for Anaphase?. CT: At the moment we are getting ready for Christmas to get all of our stock ready ... I feel Anaphase is like that, we sell clothing like a lot of shops do, candles like Yankee but you find ways to attract ... Meet The Business # 22: Anaphase Store. Carly Thompsett has a history of life and career pattern that is an example to any ...
SHAMPO ANAPHASE KUNDER RENIES SE FLOKUT 200ML. Anaphase është plotësues i përkryer i kurave kundër rënies së flokut,sepse ai ...
Occasional hair loss linked to stress, fatigue, pregnancy, changes in season, and so forth.
Anaphase. It is the most vital and critical stage of the mitosis, which makes sure equal distribution of chromatids in the ... The most important and critical phase is anaphase which makes sure the equal distribution of chromosomes to both new daughter ... Karyokinesis further divided into prophase, metaphase, anaphase, and telophase. In the prophase, there is the arrangement of ... Karyokinesis can further be divided into prophase, metaphase, anaphase, and telophase for thorough understanding, though it is ...
Anaphase, a fundamental step in the process of cell division, plays a crucial role in ensuring accurate genetic information ... Overview of Anaphase. Anaphase: The Third Stage of Mitosis. Anaphase is the third stage taking place within the process of ... On the other hand, in the process of meiosis, anaphase occurs twice - termed as Anaphase I and Anaphase II - seeing as meiosis ... Anaphase. September 15, 2023. September 15, 2023. by Ruturaj Mundhe Anaphase, a fundamental step in the process of cell ...
Upon entry into anaphase, however, the linkages that hold the two sister DNAs must be rapidly destroyed to allow physical ... Anaphase cells must therefore possess mechanisms that ensure faithful segregation of single chromatids that are now attached ... and the anaphase-specific changes that ensure proper segregation of single chromatids during the later stages of mitosis. ... Upon entry into anaphase, however, the linkages that hold the two sister DNAs must be rapidly destroyed to allow physical ...
See Article p.227 and Letter p.274 The large size of the anaphase-promoting complex or cyclosome (APC/C) and its low natural ... One of the most complex ubiquitin ligases is the anaphase-promoting complex (APC) - a 1.5-megadalton assemblage of 1-2 copies ... Mechanisms for the temporal regulation of substrate ubiquitination by the anaphase-promoting complex/cyclosome *Shivangee ... Mechanisms for the temporal regulation of substrate ubiquitination by the anaphase-promoting complex/cyclosome *Shivangee ...
Ducray Anaphase Plus Hair Loss Conditioner provides the necessary vitamins and nutrients for maintaining healthy and lustrous ...
post-anaphase microtubule array organization. Ontology. biological_process. Synonyms. PAA organization, post-anaphase array ... Parents of post-anaphase microtubule array organization (GO:1904186) subject. relation. object. ... post-anaphase microtubule array organization is_a cellular component organization (GO:0016043) ... Link to all direct and indirect annotations to post-anaphase microtubule array organization. Link to all direct and indirect ...
People who are experiencing hair loss may benefit from using the Ducray Anaphase+ Anti-Hair Loss Complement Shampoo, which is a shampoo that both strengthens and stimulates the hair.| Ducray
Phenotype data for mouse gene Anapc4. Discover Anapc4s significant phenotypes, expression, images, histopathology and more. Data for gene Anapc4 is all freely available for download.
The Anaphase Promoting Complex/Cyclosome. Like other E3 ubiquitin ligases, the Anaphase Promoting Complex/Cyclosome (APC/C) ... Skp2 is targeted for degradation by the Anaphase Promoting Complex/Cyclosome during G1-phase of the cell cycle [48, 49]. The ... Degradation of the SCF component Skp2 in cell-cycle phase G1 by the anaphase-promoting complex. Nature. 2004;. 428. :194-198. ... Zhang J, Wan L, Dai X, Sun Y, Wei W. Functional characterization of anaphase promoting complex/Cyclosome (APC/C) E3 ubiquitin ...
Although Cdc14 activity is thought to be restricted to anaphase, we found that dephosphorylation of the Dsn1 kinetochore ... These data suggest that there is a nonnucleolar pool of active Cdc14 prior to anaphase. ... Anaphase, CDC2 Protein Kinase, Cell Cycle Proteins, Chromosomal Proteins, Non-Histone, Kinetochores, Mitosis, Phosphorylation, ... Cdc14-dependent dephosphorylation of a kinetochore protein prior to anaphase in Saccharomyces cerevisiae. ...
Shop 44 1/2: Live & Unreleased Works [CD & DVD] at Best Buy. Find low everyday prices and buy online for delivery or in-store pick-up. Price Match Guarantee.
Some scientists classify this portion of anaphase as anaphase A. During the second half of anaphase, sometimes known as ... Anaphase. Anaphase is the fourth phase of mitosis in which sister chromatids separate and are pulled to the opposite poles of ... Anaphase follows metaphase. In anaphase, the proteins binding sister chromatids together at their centromeres break down. This ... A cohesin protein helps bind sister chromatids together at the centromere until they separate during anaphase. A condensin is a ...
  • Anaphase (from Ancient Greek ἀνα- (ana-) 'back, backward', and φάσις (phásis) 'appearance') is the stage of mitosis after the process of metaphase, when replicated chromosomes are split and the newly-copied chromosomes (daughter chromatids) are moved to opposite poles of the cell. (wikipedia.org)
  • A combination of different forces have been observed acting on chromatids in anaphase A, but the primary force is exerted centrally. (wikipedia.org)
  • In essence, Activation of the Anaphase-promoting complex (APC) causes the APC to cleave the M-phase cyclin and the inhibitory protein securin which activates the separase protease to cleave the cohesin subunits holding the chromatids together. (wikipedia.org)
  • Our exploration will range from a broad overview to an intricate, detailed examination of the series of events that transpire during anaphase, commencing with the separation of sister chromatids to their migration towards opposite cell poles. (biologyideas.com)
  • By definition, anaphase is a phase of mitosis wherein the replicated chromosomes, known as sister chromatids, separate from one another and move toward opposite poles of the cell. (biologyideas.com)
  • Initiating the anaphase, a protein known as separase cleaves the cohesins, proteins that hold the sister chromatids together. (biologyideas.com)
  • Upon entry into anaphase, however, the linkages that hold the two sister DNAs must be rapidly destroyed to allow physical separation of chromatids. (ox.ac.uk)
  • Anaphase cells must therefore possess mechanisms that ensure faithful segregation of single chromatids that are now attached stably to the spindle in a manner no longer dependent on tension. (ox.ac.uk)
  • In the present review, we discuss the nature of the cohesive forces that hold sister chromatids together, the mechanisms that trigger their physical separation, and the anaphase-specific changes that ensure proper segregation of single chromatids during the later stages of mitosis. (ox.ac.uk)
  • n. the separation of pairs of homologous chromosomes during meiosis or of the chromatids of a chromosome during anaphase of mitosis or meiosis. (oxfordreference.com)
  • The anaphase-promoting complex (APC) or cyclosome is a multi-subunit E3 protein ubiquitin ligase that regulates important events in mitosis, such as the initiation of anaphase and exit from telophase. (embl-heidelberg.de)
  • Separase is a caspase-like cysteine protease, which plays a central role in triggering ANAPHASE by cleaving the SCC1/RAD21 subunit of the cohesin complex. (bvsalud.org)
  • The anaphase-promoting complex/cyclosome (APC/C) is a multisubunit ubiquitin ligase that regulates progression through the cell cycle by marking key cell division proteins for destruction. (ugent.be)
  • The onset of anaphase is triggered by activation of the anaphase promoting complex/cyclosome (APC/C), following silencing of the spindle assembly checkpoint (SAC). (warwick.ac.uk)
  • The switch from metaphase to anaphase is a critical event, powered by the Anaphase-Promoting Complex/Cyclosome (APC/C). Essentially, this is a signal within the cell stating that the chromosomes have been properly aligned on the metaphase plate, signifying their readiness for separation. (biologyideas.com)
  • Here, using cryogenic electron microscopy and cryoDRGN, the authors delineate how the anaphase-promoting complex/cyclosome is reconfigurated to interact with its cognate E2s and thus polyubiquitinate its target. (nature.com)
  • Unexpectedly, multiple ubiquitin moieties are shown to interact with the anaphase-promoting complex/cyclosome machinery, including its activator Cdh1. (nature.com)
  • The anaphase promoting complex or cyclosome (APC2) is an E3 ubiquitin ligase which is part of the SCF family of ubiquitin ligases. (embl-heidelberg.de)
  • The anaphase-promoting complex or cyclosome (APC) is an unusuallycomplicated ubiquitin ligase, composed of 13 core subunits and either oftwo loosely associated regulatory subunits, Cdc20 and Cdh1. (embl-heidelberg.de)
  • Once anaphase is complete, the cell moves into telophase. (wikipedia.org)
  • The definitions get a bit tricky during anaphase (and telophase). (himelblog.com)
  • Karyokinesis can further be divided into prophase, metaphase, anaphase, and telophase for thorough understanding, though it is a constant process. (guyhowto.com)
  • Mitosis includes prophase, prometaphase, metaphase, and anaphase, as well as telophase, during which chromosome copies are carefully separated in preparation for cytokinesis, where the cytoplasm divides. (coursehero.com)
  • Chromosomes also reach their overall maximum condensation in late anaphase, to help chromosome segregation and the re-formation of the nucleus. (wikipedia.org)
  • Anaphase B spindle elongation contributes to chromosome segregation during Drosophila melanogaster embryo mitosis. (escholarship.org)
  • The first of these, anaphase A, moves chromosomes to either pole of a dividing cell (marked by centrosomes, from which mitotic microtubules are generated and organised). (wikipedia.org)
  • Furthermore, we delve into the significant role of the mitotic spindle, the complex that serves as the catalyst for moving chromosomes during anaphase, and observe the consequential fallout in case of anaphase errors, putting emphasis on common mishaps like non-disjunction which could potentially trigger chromosomal disorders including cancer and Down syndrome. (biologyideas.com)
  • the moving apart of chromosomes during anaphase of mitotic or meiotic. (oxfordreference.com)
  • Emi1 is a mitotic regulator that interacts with Cdc20 and inhibits the anaphase promoting complex. (nih.gov)
  • After 24 hr of exposure to either SWCNT or vanadium pentoxide, fragmented centrosomes, multiple mitotic spindle poles, anaphase bridges, and aneuploid chromosome number were observed. (cdc.gov)
  • Lastly, to enrich comprehension, there will be a comparison of anaphase in both mitosis and meiosis, finding the delicate differences and distinctive features of each process. (biologyideas.com)
  • Both in mitosis and meiosis, anaphase ensures each newly formed cell has a complete and accurate set of chromosomes, thus safeguarding the genetic integrity of an organism. (biologyideas.com)
  • The separation of homologous chromosomes at the anaphase stage of mitosis and meiosis , and movement towards the poles of the nuclear spindle. (oxfordreference.com)
  • Anaphase starts when the anaphase promoting complex marks an inhibitory chaperone called securin for destruction by ubiquitylating it. (wikipedia.org)
  • One of the most complex ubiquitin ligases is the anaphase-promoting complex (APC) - a 1.5-megadalton assemblage of 1-2 copies of each of 13 different subunits, as well as two diffusible activators. (nature.com)
  • Loss of HDAC8 activity results in increased SMC3 acetylation and inefficient dissolution of the 'used' cohesin complex released from chromatin in both prophase and anaphase. (nih.gov)
  • An architectural map of the anaphase-promoting complex. (embl-heidelberg.de)
  • Although the positioning signal is likely to be transmitted via the anaphase microtubule array to the cell cortex, exactly how the microtubule array determines the site of contractile ring formation remains unresolved. (biologists.com)
  • A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly ofa post-anaphase microtubule array. (planteome.org)
  • Link to all annotated objects annotated to post-anaphase microtubule array organization. (planteome.org)
  • Link to all direct and indirect annotations to post-anaphase microtubule array organization. (planteome.org)
  • Anaphase is the third stage taking place within the process of mitosis, following prophase and metaphase. (biologyideas.com)
  • The second motion, anaphase B, involves the separation of these poles from each other. (wikipedia.org)
  • In this paper, we present evidence that anaphase B is induced by the minus end-stabilizing protein patronin, which antagonizes the kinesin-13 depolymerase KLP10A at spindle poles, thereby switching off the depolymerization of the minus ends of outwardly sliding ipMTs to suppress flux. (escholarship.org)
  • Cdc14-dependent dephosphorylation of a kinetochore protein prior to anaphase in Saccharomyces cerevisiae. (ox.ac.uk)
  • Although Cdc14 activity is thought to be restricted to anaphase, we found that dephosphorylation of the Dsn1 kinetochore protein in metaphase requires Cdc14. (ox.ac.uk)
  • In spite of the meticulous processes that normally ensure accurate chromosome separation, errors during anaphase can still occur, leading to chromosomal instability and disease. (biologyideas.com)
  • Dual-channel spinning-disk confocal time-lapse movie showing anaphase relative to poleward microtubule flux. (cellimagelibrary.org)
  • the separation of chromosomes at anaphase during nuclear. (oxfordreference.com)
  • disjunction The separation of the two members of each pair of homologous chromosomes that occurs during meiotic anaphase. (oxfordreference.com)
  • We previously discovered that CDK2 inhibition causes lung cancer cells with more than two centrosomes to undergo multipolar cell division leading to apoptosis, defined as anaphase catastrophe. (elsevierpure.com)
  • Live-cell imaging provided direct evidence that following CDK2 inhibition, lung cancer cells develop multipolar anaphase and undergo multipolar cell division with the resulting progeny apoptotic. (elsevierpure.com)
  • Thus, CP110 is a critical mediator of CDK2 inhibition-driven anaphase catastrophe. (elsevierpure.com)
  • The second part of anaphase is driven by its own distinct mechanisms. (wikipedia.org)
  • Mechanisms of CDK2-mediated anaphase catastrophe and how activated KRAS enhances this effect were investigated. (elsevierpure.com)
  • It begins with the regulated triggering of the metaphase-to-anaphase transition. (wikipedia.org)
  • The presence of a single, lagging chromosome is sufficient to activate the checkpoint, producing a delay at the metaphase-anaphase transition until the last spindle attachment is made. (columbia.edu)
  • These data support a model in which Tum/RacGAP, via its interaction with Pbl, provides a critical link between the anaphase microtubule spindle and cytokinetic furrow formation in Drosophila cells. (biologists.com)
  • Anaphase is a key biological process that takes place during cell division, specifically in the broader context of mitosis. (biologyideas.com)
  • The most important and critical phase is anaphase which makes sure the equal distribution of chromosomes to both new daughter cells. (guyhowto.com)
  • Anaphase holds vast importance in the division of cells and ensuring genetic continuity. (biologyideas.com)
  • Not limited to mitosis, anaphase also takes place in meiosis, another type of cell division that leads to the creation of sex cells. (biologyideas.com)
  • Anaphase, a fundamental step in the process of cell division, plays a crucial role in ensuring accurate genetic information transfer. (biologyideas.com)
  • The main tagline for Anaphase Store has always been 'upstage your life' by selling different and unique t-shirt designs, scents that go with seasons, and homemade bath bombs. (midlandstraveller.com)
  • I've seen a few textbooks that say the chromosome number in the cell doubles in anaphase (i.e. a human cell has 46 chromosomes in metaphase and 92 in anaphase). (himelblog.com)
  • Anaphase marks a pivotal stage in mitosis, crucially ensuring each resulting daughter cell inherits an accurate set of chromosomes. (biologyideas.com)
  • Thus, anaphase and its precise execution are crucial for maintaining genetic stability and cellular health. (biologyideas.com)