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Apaf-1
Apoptotic protease activating factor 1, also known as APAF1, is a human homolog of ''C. elegans'' CED-4 gene. Function The protein was identified in the lab of Xiaodong Wang as an activator of caspase-3 in the presense of cytochromeC and dATP. This gene encodes a cytoplasmic protein that forms one of the central hubs in the apoptosis regulatory network. This protein contains (from the N terminal) a caspase recruitment domain ( CARD), an ATPase domain (NB-ARC), few short helical domains and then several copies of the WD40 repeat domain. Upon binding cytochrome c and dATP, this protein forms an oligomeric apoptosome. The apoptosome binds and cleaves Procaspase-9 protein, releasing its mature, activated form. The precise mechanism for this reaction is still debated though work published by Guy Salvesen suggests that the apoptosome may induce caspase-9 dimerization and subsequent autocatalysis. Activated caspase-9 stimulates the subsequent caspase cascade that commits the cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosome
The apoptosome is a large quaternary protein structure formed in the process of apoptosis. Its formation is triggered by the release of cytochrome c from the mitochondria in response to an internal (intrinsic) or external (extrinsic) cell death stimulus. Stimuli can vary from DNA damage and viral infection to developmental cues such as those leading to the degradation of a tadpole's tail. In mammalian cells, once cytochrome c is released, it binds to the cytosolic protein Apaf-1 to facilitate the formation of an apoptosome. An early biochemical study suggests a two-to-one ratio of cytochrome c to apaf-1 for apoptosome formation. However, recent structural studies suggest the cytochrome c to apaf-1 ratio is one-to-one. It has also been shown that the nucleotide dATP as third component binds to apaf-1, however its exact role is still debated. The mammalian apoptosome had never been crystallized, but a human APAF-1/cytochrome-c apoptosome has been imaged at lower (2 nm) resolutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caspase-9
Caspase-9 is an enzyme that in humans is encoded by the CASP9 gene. It is an initiator caspase, critical to the apoptotic pathway found in many tissues. Caspase-9 homologs have been identified in all mammals for which they are known to exist, such as ''Mus musculus'' and ''Pan troglodytes''. Caspase-9 belongs to a family of caspases, cysteine-aspartic proteases involved in apoptosis and cytokine signalling. Apoptotic signals cause the release of cytochrome c from mitochondria and activation of apaf-1 ( apoptosome), which then cleaves the pro-enzyme of caspase-9 into the active dimer form. Regulation of this enzyme occurs through phosphorylation by an allosteric inhibitor, inhibiting dimerization and inducing a conformational change. Correct caspase-9 function is required for apoptosis, leading to the normal development of the central nervous system. Caspase-9 has multiple additional cellular functions that are independent of its role in apoptosis. Nonapoptotic roles of caspas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caspase-9
Caspase-9 is an enzyme that in humans is encoded by the CASP9 gene. It is an initiator caspase, critical to the apoptotic pathway found in many tissues. Caspase-9 homologs have been identified in all mammals for which they are known to exist, such as ''Mus musculus'' and ''Pan troglodytes''. Caspase-9 belongs to a family of caspases, cysteine-aspartic proteases involved in apoptosis and cytokine signalling. Apoptotic signals cause the release of cytochrome c from mitochondria and activation of apaf-1 ( apoptosome), which then cleaves the pro-enzyme of caspase-9 into the active dimer form. Regulation of this enzyme occurs through phosphorylation by an allosteric inhibitor, inhibiting dimerization and inducing a conformational change. Correct caspase-9 function is required for apoptosis, leading to the normal development of the central nervous system. Caspase-9 has multiple additional cellular functions that are independent of its role in apoptosis. Nonapoptotic roles of caspas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BCL2-like 1 (gene)
Bcl-2-like protein 1 is a protein encoded in humans by the ''BCL2L1'' gene. Through alternative splicing, the gene encodes both of the human proteins Bcl-xL and Bcl-xS. Function The protein encoded by this gene belongs to the Bcl-2 protein family. Bcl-2 family members form hetero- or homodimers and act as anti- or pro- apoptotic regulators that are involved in a wide variety of cellular activities. The proteins encoded by this gene are located at the outer mitochondrial membrane, and have been shown to regulate outer mitochondrial membrane channel ( voltage-dependent anion channels (VDACs) opening. VDACs regulate mitochondrial membrane potential, and thus controls the production of reactive oxygen species and release of cytochrome C by mitochondria, both of which are the potent inducers of cell apoptosis. Two alternatively spliced transcript variants, which encode distinct isoforms, have been reported. The longer isoform ( Bcl-xL) acts as an apoptotic inhibitor and the shor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosis
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes ( morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, DNA fragmentation, and mRNA decay. The average adult human loses between 50 and 70 billion cells each day due to apoptosis. For an average human child between eight and fourteen years old, approximately twenty to thirty billion cells die per day. In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo occurs because cells between the digits undergo apoptosis. Unlike necrosis, apoptosis produces cell fragments called apop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiaodong Wang (biochemist)
Xiaodong Wang (, born 1963) is a Chinese biochemist best known for his work with cytochrome c. His laboratory developed an ''in vitro'' assay for the activation of the apoptosis related proteinase Caspase-3. This allowed the biochemical purification of a complex of Cytochrome c, Caspase-9 and the Apoptotic Protease Activating factor-1 (APAF1). These components are essential for forming a ternary complex called the apoptosome that activates Caspase-3 downstream of the intracellular or mitochondrial pathway of apoptosis. He was awarded the 2006 Shaw Prize in Life Science and Medicine. Wang is a member of United States National Academy of Sciences and the Howard Hughes Medical Institute. Currently he is the director of the National Institute of Biological Sciences, Beijing. Honors & awards * 2020, King Faisal International Prize in Medicine. * 2007, Richard Lounsbery Award, from the National Academy of Sciences, USA * 2006, Shaw Prize, from the Shaw Foundation * 2004, NAS Awar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HSPA4
Heat shock 70 kDa protein 4 is a protein that in humans is encoded by the ''HSPA4'' gene. The protein encoded by this gene was originally suggested to be a member of the heat shock protein 70 family. However it is now known that human HSPA4 is an equivalent to mouse the Apg-2 protein and is a member of the Hsp110 family. Interactions HSPA4 has been shown to interact with: * APAF1 * DNAJB1, * HDAC1, * HSF1, * HSPBP1, * Histone deacetylase 2 Histone deacetylase 2 (HDAC2) is an enzyme that in humans is encoded by the ''HDAC2'' gene. It belongs to the histone deacetylase class of enzymes responsible for the removal of acetyl groups from lysine residues at the N-terminal region of the co ..., * NAD(P)H dehydrogenase (quinone 1), * STUB1, and * TTC1. References Further reading * * * * * * * * * * * * * * * * * * * External links * {{Chaperones Heat shock proteins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
APIP
APAF1-interacting protein is a protein that in humans is encoded by the ''APIP'' gene. It is an enzyme with Methylthioribulose 1-phosphate dehydratase activity which is involved in the methionine salvage pathway. APIP deficiency is associated with cell death and cancer. Interactions APIP has been shown to interact with APAF1 Apoptotic protease activating factor 1, also known as APAF1, is a human homolog of ''C. elegans'' CED-4 gene. Function The protein was identified in the lab of Xiaodong Wang as an activator of caspase-3 in the presense of cytochromeC and dATP .... References External links * Further reading * * * * * {{gene-11-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programmed Cell Death
Programmed cell death (PCD; sometimes referred to as cellular suicide) is the death of a cell (biology), cell as a result of events inside of a cell, such as apoptosis or autophagy. PCD is carried out in a biological process, which usually confers advantage during an organism's biological life cycle, lifecycle. For example, the Limb development, differentiation of fingers and toes in a developing human embryo occurs because cells between the fingers apoptose; the result is that the digits are separate. PCD serves fundamental functions during both plant and animal tissue development. Apoptosis and autophagy are both forms of programmed cell death. Necrosis is the death of a cell caused by external factors such as trauma or infection and occurs in several different forms. Necrosis was long seen as a non-physiological process that occurs as a result of infection or injury, but in the 2000s, a form of programmed necrosis, called necroptosis, was recognized as an alternative form of pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome C
The cytochrome complex, or cyt ''c'', is a small hemeprotein found loosely associated with the inner membrane of the mitochondrion. It belongs to the cytochrome c family of proteins and plays a major role in cell apoptosis. Cytochrome c is highly water-soluble, unlike other cytochromes, and is an essential component of the respiratory electron transport chain, where it carries one electron. It is capable of undergoing oxidation and reduction as its iron atom converts between the ferrous and ferric forms, but does not bind oxygen. It transfers electrons between Complexes III (Coenzyme Q – Cyt c reductase) and IV (Cyt c oxidase). In humans, cytochrome c is encoded by the ''CYCS'' gene. Species distribution Cytochrome c is a highly conserved protein across the spectrum of eukaryotic species, found in plants, animals, fungi, and many unicellular organisms. This, along with its small size (molecular weight about 12,000 daltons), makes it useful in studies of cladistics. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guy Salvesen
Guy Salvesen is a South African-born biochemist, best known for his work in the field of apoptosis. His research focuses on proteases and their inhibitors in humans, with particular emphasis on the caspases of the apoptotic cell death pathway. His PhD in biochemistry is from the University of Cambridge, studying under Alan Barrett (1981). His first posts were at the Strangeways Research Laboratory and MRC Laboratory of Molecular Biology in Cambridge. In 1985, Salvesen moved to the USA, taking up a position at the University of Georgia. He joined the faculty of Duke University in 1987, and moved his laboratory to the Sanford-Burnham Institute for Medical Research, La Jolla, California in 1996. As of 2007, Salvesen is the Program Director in Apoptosis and Cell Death Research at the Sanford-Burnham Institute. He also holds an Assistant Professorship at Duke University. He served as the Vice-Chair (the Americas) of the ''Biochemical Journal The ''Biochemical Journal'' is a peer-re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
