Caspase 3
Caspase 9
A long pro-domain caspase that contains a caspase recruitment domain in its pro-domain region. Caspase 9 is activated during cell stress by mitochondria-derived proapoptotic factors and by CARD SIGNALING ADAPTOR PROTEINS such as APOPTOTIC PROTEASE-ACTIVATING FACTOR 1. It activates APOPTOSIS by cleaving and activating EFFECTOR CASPASES.
Caspase Inhibitors
Caspase 8
A long pro-domain caspase that contains a death effector domain in its pro-domain region. Caspase 8 plays a role in APOPTOSIS by cleaving and activating EFFECTOR CASPASES. Activation of this enzyme can occur via the interaction of its N-terminal death effector domain with DEATH DOMAIN RECEPTOR SIGNALING ADAPTOR PROTEINS.
Caspase 7
Caspases
A family of intracellular CYSTEINE ENDOPEPTIDASES that play a role in regulating INFLAMMATION and APOPTOSIS. They specifically cleave peptides at a CYSTEINE amino acid that follows an ASPARTIC ACID residue. Caspases are activated by proteolytic cleavage of a precursor form to yield large and small subunits that form the enzyme. Since the cleavage site within precursors matches the specificity of caspases, sequential activation of precursors by activated caspases can occur.
Caspase 1
A long pro-domain caspase that has specificity for the precursor form of INTERLEUKIN-1BETA. It plays a role in INFLAMMATION by catalytically converting the inactive forms of CYTOKINES such as interleukin-1beta to their active, secreted form. Caspase 1 is referred as interleukin-1beta converting enzyme and is frequently abbreviated ICE.
Caspase 10
A long pro-domain caspase that contains a death effector domain in its pro-domain region. Activation of this enzyme can occur via the interaction of its N-terminal death effector domain with DEATH DOMAIN RECEPTOR SIGNALING ADAPTOR PROTEINS. Caspase 10 plays a role in APOPTOSIS by cleaving and activating EFFECTOR CASPASES. Several isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.
Apoptosis
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
Amino Acid Chloromethyl Ketones
Cysteine Proteinase Inhibitors
Caspase 12
Caspase 14
Enzyme Activation
DNA Fragmentation
Proto-Oncogene Proteins c-bcl-2
Membrane proteins encoded by the BCL-2 GENES and serving as potent inhibitors of cell death by APOPTOSIS. The proteins are found on mitochondrial, microsomal, and NUCLEAR MEMBRANE sites within many cell types. Overexpression of bcl-2 proteins, due to a translocation of the gene, is associated with follicular lymphoma.
Cytochromes c
Mitochondria
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)
Antigens, CD95
A tumor necrosis factor receptor subtype found in a variety of tissues and on activated LYMPHOCYTES. It has specificity for FAS LIGAND and plays a role in regulation of peripheral immune responses and APOPTOSIS. Multiple isoforms of the protein exist due to multiple ALTERNATIVE SPLICING. The activated receptor signals via a conserved death domain that associates with specific TNF RECEPTOR-ASSOCIATED FACTORS in the CYTOPLASM.
Cytochrome c Group
X-Linked Inhibitor of Apoptosis Protein
Poly(ADP-ribose) Polymerases
Apoptotic Protease-Activating Factor 1
bcl-2-Associated X Protein
Cell Death
Inhibitor of Apoptosis Proteins
A conserved class of proteins that control APOPTOSIS in both VERTEBRATES and INVERTEBRATES. IAP proteins interact with and inhibit CASPASES, and they function as ANTI-APOPTOTIC PROTEINS. The protein class is defined by an approximately 80-amino acid motif called the baculoviral inhibitor of apoptosis repeat.
Jurkat Cells
Caspases, Initiator
A subtype of caspases that contain long pro-domain regions that regulate the activation of the enzyme. The pro-domain regions contain protein-protein interaction motifs that can interact with specific signaling adaptor proteins such as DEATH DOMAIN RECEPTORS; DED SIGNALING ADAPTOR PROTEINS; and CARD SIGNALING ADAPTOR PROTEINS. Once activated, the initiator caspases can activate other caspases such as the EFFECTOR CASPASES.
In Situ Nick-End Labeling
An in situ method for detecting areas of DNA which are nicked during APOPTOSIS. Terminal deoxynucleotidyl transferase is used to add labeled dUTP, in a template-independent manner, to the 3 prime OH ends of either single- or double-stranded DNA. The terminal deoxynucleotidyl transferase nick end labeling, or TUNEL, assay labels apoptosis on a single-cell level, making it more sensitive than agarose gel electrophoresis for analysis of DNA FRAGMENTATION.
Cell Survival
BH3 Interacting Domain Death Agonist Protein
Apoptosis Regulatory Proteins
Signal Transduction
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Cysteine Endopeptidases
Fas-Associated Death Domain Protein
A signal-transducing adaptor protein that associates with TNF RECEPTOR complexes. It contains a death effector domain that can interact with death effector domains found on INITIATOR CASPASES such as CASPASE 8 and CASPASE 10. Activation of CASPASES via interaction with this protein plays a role in the signaling cascade that leads to APOPTOSIS.
Enzyme Inhibitors
bcl-X Protein
Apoptosis Inducing Factor
A flavoprotein that functions as a powerful antioxidant in the MITOCHONDRIA and promotes APOPTOSIS when released from the mitochondria. In mammalian cells AIF is released in response to pro-apoptotic protein members of the bcl-2 protein family. It translocates to the CELL NUCLEUS and binds DNA to stimulate CASPASE-independent CHROMATIN condensation.
Blotting, Western
Tumor Cells, Cultured
Cells, Cultured
CASP8 and FADD-Like Apoptosis Regulating Protein
An APOPTOSIS-regulating protein that is structurally related to CASPASE 8 and competes with CASPASE 8 for binding to FAS ASSOCIATED DEATH DOMAIN PROTEIN. Two forms of CASP8 and FADD-like apoptosis regulating protein exist, a long form containing a caspase-like enzymatically inactive domain and a short form which lacks the caspase-like domain.
Staurosporine
Annexin A5
Membrane Potential, Mitochondrial
Carrier Proteins
HL-60 Cells
A promyelocytic cell line derived from a patient with ACUTE PROMYELOCYTIC LEUKEMIA. HL-60 cells lack specific markers for LYMPHOID CELLS but express surface receptors for FC FRAGMENTS and COMPLEMENT SYSTEM PROTEINS. They also exhibit phagocytic activity and responsiveness to chemotactic stimuli. (From Hay et al., American Type Culture Collection, 7th ed, pp127-8)
TNF-Related Apoptosis-Inducing Ligand
A transmembrane-protein belonging to the TNF family of intercellular signaling proteins. It is a widely expressed ligand that activates APOPTOSIS by binding to TNF-RELATED APOPTOSIS-INDUCING LIGAND RECEPTORS. The membrane-bound form of the protein can be cleaved by specific CYSTEINE ENDOPEPTIDASES to form a soluble ligand form.
HeLa Cells
Necrosis
The pathological process occurring in cells that are dying from irreparable injuries. It is caused by the progressive, uncontrolled action of degradative ENZYMES, leading to MITOCHONDRIAL SWELLING, nuclear flocculation, and cell lysis. It is distinct it from APOPTOSIS, which is a normal, regulated cellular process.
Caspases, Effector
Apoptosomes
Multimeric protein complexes formed in the CYTOSOL that play a role in the activation of APOPTOSIS. They can occur when MITOCHONDRIA become damaged due to cell stress and release CYTOCHROME C. Cytosolic cytochrome C associates with APOPTOTIC PROTEASE-ACTIVATING FACTOR 1 to form the apoptosomal protein complex. The apoptosome signals apoptosis by binding to and activating specific INITIATOR CASPASES such as CASPASE 9.
Reactive Oxygen Species
Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.
Tumor Necrosis Factor-alpha
Serum glycoprotein produced by activated MACROPHAGES and other mammalian MONONUCLEAR LEUKOCYTES. It has necrotizing activity against tumor cell lines and increases ability to reject tumor transplants. Also known as TNF-alpha, it is only 30% homologous to TNF-beta (LYMPHOTOXIN), but they share TNF RECEPTORS.
Transfection
Proteins
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
CRADD Signaling Adaptor Protein
Intracellular Signaling Peptides and Proteins
Proteins and peptides that are involved in SIGNAL TRANSDUCTION within the cell. Included here are peptides and proteins that regulate the activity of TRANSCRIPTION FACTORS and cellular processes in response to signals from CELL SURFACE RECEPTORS. Intracellular signaling peptide and proteins may be part of an enzymatic signaling cascade or act through binding to and modifying the action of other signaling factors.
Death Domain Receptor Signaling Adaptor Proteins
Dose-Response Relationship, Drug
Flow Cytometry
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
Phosphatidylserines
CARD Signaling Adaptor Proteins
A family of intracellular signaling adaptor proteins that contain caspase activation and recruitment domains. Proteins that contain this domain play a role in APOPTOSIS-related signal transduction by associating with other CARD domain-containing members and in activating INITIATOR CASPASES that contain CARD domains within their N-terminal pro-domain region.
bcl-2 Homologous Antagonist-Killer Protein
Calpain
Cysteine proteinase found in many tissues. Hydrolyzes a variety of endogenous proteins including NEUROPEPTIDES; CYTOSKELETAL PROTEINS; proteins from SMOOTH MUSCLE; CARDIAC MUSCLE; liver; platelets; and erythrocytes. Two subclasses having high and low calcium sensitivity are known. Removes Z-discs and M-lines from myofibrils. Activates phosphorylase kinase and cyclic nucleotide-independent protein kinase. This enzyme was formerly listed as EC 3.4.22.4.
Granzymes
Proto-Oncogene Proteins
Mitochondrial Proteins
Tumor Suppressor Protein p53
Receptor-Interacting Protein Serine-Threonine Kinases
A family of serine-threonine kinases that plays a role in intracellular signal transduction by interacting with a variety of signaling adaptor proteins such as CRADD SIGNALING ADAPTOR PROTEIN; TNF RECEPTOR-ASSOCIATED FACTOR 2; and TNF RECEPTOR-ASSOCIATED DEATH DOMAIN PROTEIN. Although they were initially described as death domain-binding adaptor proteins, members of this family may contain other protein-binding domains such as those involving caspase activation and recruitment.
Antineoplastic Agents, Phytogenic
RNA, Small Interfering
Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.
Amino Acid Sequence
Receptors, Tumor Necrosis Factor
Receptors, TNF-Related Apoptosis-Inducing Ligand
Tumor necrosis factor receptor family members that are widely expressed and play a role in regulation of peripheral immune responses and APOPTOSIS. The receptors are specific for TNF-RELATED APOPTOSIS-INDUCING LIGAND and signal via conserved death domains that associate with specific TNF RECEPTOR-ASSOCIATED FACTORS in the CYTOPLASM.
Cytosol
bcl-Associated Death Protein
Molecular Sequence Data
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.
NF-kappa B
Serpins
A family of serine proteinase inhibitors which are similar in amino acid sequence and mechanism of inhibition, but differ in their specificity toward proteolytic enzymes. This family includes alpha 1-antitrypsin, angiotensinogen, ovalbumin, antiplasmin, alpha 1-antichymotrypsin, thyroxine-binding protein, complement 1 inactivators, antithrombin III, heparin cofactor II, plasminogen inactivators, gene Y protein, placental plasminogen activator inhibitor, and barley Z protein. Some members of the serpin family may be substrates rather than inhibitors of SERINE ENDOPEPTIDASES, and some serpins occur in plants where their function is not known.
JNK Mitogen-Activated Protein Kinases
Etoposide
A semisynthetic derivative of PODOPHYLLOTOXIN that exhibits antitumor activity. Etoposide inhibits DNA synthesis by forming a complex with topoisomerase II and DNA. This complex induces breaks in double stranded DNA and prevents repair by topoisomerase II binding. Accumulated breaks in DNA prevent entry into the mitotic phase of cell division, and lead to cell death. Etoposide acts primarily in the G2 and S phases of the cell cycle.
U937 Cells
Genes, bcl-2
Adaptor Proteins, Signal Transducing
A broad category of carrier proteins that play a role in SIGNAL TRANSDUCTION. They generally contain several modular domains, each of which having its own binding activity, and act by forming complexes with other intracellular-signaling molecules. Signal-transducing adaptor proteins lack enzyme activity, however their activity can be modulated by other signal-transducing enzymes
Mitochondrial Membranes
The two lipoprotein layers in the MITOCHONDRION. The outer membrane encloses the entire mitochondrion and contains channels with TRANSPORT PROTEINS to move molecules and ions in and out of the organelle. The inner membrane folds into cristae and contains many ENZYMES important to cell METABOLISM and energy production (MITOCHONDRIAL ATP SYNTHASE).
Models, Biological
Down-Regulation
Ceramides
Immunoblotting
Neurons
Protein Structure, Tertiary
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Cell Cycle
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.
Phosphorylation
Reverse Transcriptase Polymerase Chain Reaction
Microscopy, Fluorescence
Mice, Knockout
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
Receptor-Interacting Protein Serine-Threonine Kinase 2
Protein Synthesis Inhibitors
Compounds which inhibit the synthesis of proteins. They are usually ANTI-BACTERIAL AGENTS or toxins. Mechanism of the action of inhibition includes the interruption of peptide-chain elongation, the blocking the A site of ribosomes, the misreading of the genetic code or the prevention of the attachment of oligosaccharide side chains to glycoproteins.
Myeloid Cell Leukemia Sequence 1 Protein
A member of the myeloid leukemia factor (MLF) protein family with multiple alternatively spliced transcript variants encoding different protein isoforms. In hematopoietic cells, it is located mainly in the nucleus, and in non-hematopoietic cells, primarily in the cytoplasm with a punctate nuclear localization. MLF1 plays a role in cell cycle differentiation.
Mutation
Up-Regulation
Drosophila Proteins
Substrate Specificity
Membrane Potentials
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
Cell Nucleus
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)
Neoplasm Proteins
Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.
Autophagy
The segregation and degradation of damaged or unwanted cytoplasmic constituents by autophagic vacuoles (cytolysosomes) composed of LYSOSOMES containing cellular components in the process of digestion; it plays an important role in BIOLOGICAL METAMORPHOSIS of amphibians, in the removal of bone by osteoclasts, and in the degradation of normal cell components in nutritional deficiency states.
RNA Interference
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.
Protein-Serine-Threonine Kinases
Coumarins
RNA, Messenger
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Protein Processing, Post-Translational
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
Oxidative Stress
Intracellular Membranes
Protein Binding
Immunohistochemistry
Mitogen-Activated Protein Kinases
A superfamily of PROTEIN-SERINE-THREONINE KINASES that are activated by diverse stimuli via protein kinase cascades. They are the final components of the cascades, activated by phosphorylation by MITOGEN-ACTIVATED PROTEIN KINASE KINASES, which in turn are activated by mitogen-activated protein kinase kinase kinases (MAP KINASE KINASE KINASES).
Propidium
Receptors, Death Domain
A family of cell surface receptors that signal via a conserved domain that extends into the cell CYTOPLASM. The conserved domain is referred to as a death domain due to the fact that many of these receptors are involved in signaling APOPTOSIS. Several DEATH DOMAIN RECEPTOR SIGNALING ADAPTOR PROTEINS can bind to the death domains of the activated receptors and through a complex series of interactions activate apoptotic mediators such as CASPASES.
Proto-Oncogene Proteins c-akt
Cycloheximide
Membrane Proteins
Rats, Sprague-Dawley
Protease Inhibitors
Drug Screening Assays, Antitumor
Receptors, Tumor Necrosis Factor, Type I
A tumor necrosis factor receptor subtype that has specificity for TUMOR NECROSIS FACTOR ALPHA and LYMPHOTOXIN ALPHA. It is constitutively expressed in most tissues and is a key mediator of tumor necrosis factor signaling in the vast majority of cells. The activated receptor signals via a conserved death domain that associates with specific TNF RECEPTOR-ASSOCIATED FACTORS in the CYTOPLASM.
p38 Mitogen-Activated Protein Kinases
A mitogen-activated protein kinase subfamily that regulates a variety of cellular processes including CELL GROWTH PROCESSES; CELL DIFFERENTIATION; APOPTOSIS; and cellular responses to INFLAMMATION. The P38 MAP kinases are regulated by CYTOKINE RECEPTORS and can be activated in response to bacterial pathogens.
Proteolysis
Protein Transport
Serine Endopeptidases
Disease Models, Animal
DNA Damage
Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.
Acetylcysteine
Proteasome Endopeptidase Complex
A large multisubunit complex that plays an important role in the degradation of most of the cytosolic and nuclear proteins in eukaryotic cells. It contains a 700-kDa catalytic sub-complex and two 700-kDa regulatory sub-complexes. The complex digests ubiquitinated proteins and protein activated via ornithine decarboxylase antizyme.
Cell-Free System
A fractionated cell extract that maintains a biological function. A subcellular fraction isolated by ultracentrifugation or other separation techniques must first be isolated so that a process can be studied free from all of the complex side reactions that occur in a cell. The cell-free system is therefore widely used in cell biology. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p166)
Ultraviolet Rays
That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.
Fibroblasts
Hydrogen Peroxide
Drug Resistance, Neoplasm
Gene Expression Regulation
Gene Expression
Endoplasmic Reticulum Stress
Epithelial Cells
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
Recombinant Fusion Proteins
Microscopy, Confocal
Cell Division
Neuroprotective Agents
Drugs intended to prevent damage to the brain or spinal cord from ischemia, stroke, convulsions, or trauma. Some must be administered before the event, but others may be effective for some time after. They act by a variety of mechanisms, but often directly or indirectly minimize the damage produced by endogenous excitatory amino acids.
Cell Line, Transformed
Lamins
Drosophila
Sequence Homology, Amino Acid
Gene Expression Regulation, Neoplastic
Microtubule-Associated Proteins
Cytoplasm
Gene Knockdown Techniques
Permeability
DNA Primers
Nuclear Proteins
Interleukin-1beta
Cathepsin B
A lysosomal cysteine proteinase with a specificity similar to that of PAPAIN. The enzyme is present in a variety of tissues and is important in many physiological and pathological processes. In pathology, cathepsin B has been found to be involved in DEMYELINATION; EMPHYSEMA; RHEUMATOID ARTHRITIS, and NEOPLASM INVASIVENESS.
Cell Differentiation
Bongkrekic Acid
Hepatocytes
Mice, Transgenic
Doxorubicin
Cytoprotection
Aspartic Acid
L-Lactate Dehydrogenase
Protein Kinase C-delta
Gene Expression Regulation, Enzymologic
Lamin Type B
Isatin
Keratin-18
Neuroblastoma
A common neoplasm of early childhood arising from neural crest cells in the sympathetic nervous system, and characterized by diverse clinical behavior, ranging from spontaneous remission to rapid metastatic progression and death. This tumor is the most common intraabdominal malignancy of childhood, but it may also arise from thorax, neck, or rarely occur in the central nervous system. Histologic features include uniform round cells with hyperchromatic nuclei arranged in nests and separated by fibrovascular septa. Neuroblastomas may be associated with the opsoclonus-myoclonus syndrome. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2099-2101; Curr Opin Oncol 1998 Jan;10(1):43-51)
Glutathione
Leupeptins
MAP Kinase Signaling System
An intracellular signaling system involving the MAP kinase cascades (three-membered protein kinase cascades). Various upstream activators, which act in response to extracellular stimuli, trigger the cascades by activating the first member of a cascade, MAP KINASE KINASE KINASES; (MAPKKKs). Activated MAPKKKs phosphorylate MITOGEN-ACTIVATED PROTEIN KINASE KINASES which in turn phosphorylate the MITOGEN-ACTIVATED PROTEIN KINASES; (MAPKs). The MAPKs then act on various downstream targets to affect gene expression. In mammals, there are several distinct MAP kinase pathways including the ERK (extracellular signal-regulated kinase) pathway, the SAPK/JNK (stress-activated protein kinase/c-jun kinase) pathway, and the p38 kinase pathway. There is some sharing of components among the pathways depending on which stimulus originates activation of the cascade.
Macrophages
The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)
Xenograft Model Antitumor Assays
Mitogen-Activated Protein Kinase 8
Endoplasmic Reticulum
A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)