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FasL
Fas ligand (FasL or CD95L or CD178) is a type-II transmembrane protein that belongs to the tumor necrosis factor (TNF) family. Its binding with its receptor induces apoptosis. Fas ligand/receptor interactions play an important role in the regulation of the immune system and the progression of cancer. Structure Fas ligand or FasL is a homotrimeric type II transmembrane protein expressed on cytotoxic T lymphocytes. It signals through trimerization of FasR, which spans the membrane of the "target" cell. This trimerization usually leads to apoptosis, or cell death. Soluble Fas ligand is generated by cleaving membrane-bound FasL at a conserved cleavage site by the external matrix metalloproteinase MMP-7. Receptors *FasR: The Fas receptor (FasR), or CD95, is the most intensely studied member of the death receptor family. The gene is situated on chromosome 10 in humans and 19 in mice. Previous reports have identified as many as eight splice variants, which are translated into se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD95
The Fas receptor, also known as Fas, FasR, apoptosis antigen 1 (APO-1 or APT), cluster of differentiation 95 (CD95) or tumor necrosis factor receptor superfamily member 6 (TNFRSF6), is a protein that in humans is encoded by the ''FAS'' gene. Fas was first identified using a monoclonal antibody generated by immunizing mice with the FS-7 cell line. Thus, the name Fas is derived from ''F''S-7-''a''ssociated ''s''urface antigen. The Fas receptor is a death receptor on the surface of cells that leads to programmed cell death ( apoptosis) if it binds its ligand, Fas ligand (FasL). It is one of two apoptosis pathways, the other being the mitochondrial pathway. Gene FAS receptor gene is located on the long arm of chromosome 10 (10q24.1) in humans and on chromosome 19 in mice. The gene lies on the plus ( Watson strand) and is 25,255 bases in length organized into nine protein encoding exons. Similar sequences related by evolution (orthologs) are found in most mammals. Protein Pre ... [...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 apopt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FADD
FAS-associated death domain protein, also called MORT1, is encoded by the ''FADD'' gene on the 11q13.3 region of chromosome 11 in humans. FADD is an adaptor protein that bridges members of the tumor necrosis factor receptor superfamily, such as the Fas-receptor, to procaspases 8 and 10 to form the death-inducing signaling complex (DISC) during apoptosis. As well as its most well known role in apoptosis, FADD has also been seen to play a role in other processes including proliferation, cell cycle regulation and development. Structure FADD is a 23 kDa protein, made up of 208 amino acids. It contains two main domains: a C terminal death domain (DD) and an N terminal death effector domain (DED). Each domain, although sharing very little sequence similarity, are structurally similar to one another, with each consisting of 6 α helices. The DD of FADD binds to receptors such as the Fas receptor at the plasma membrane via their DD. The interaction between the death domains are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytotoxic T Cell
A cytotoxic T cell (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cell or killer T cell) is a T lymphocyte (a type of white blood cell) that kills cancer cells, cells that are infected by intracellular pathogens (such as viruses or bacteria), or cells that are damaged in other ways. Most cytotoxic T cells express T-cell receptors (TCRs) that can recognize a specific antigen. An antigen is a molecule capable of stimulating an immune response and is often produced by cancer cells, viruses, bacteria or intracellular signals. Antigens inside a cell are bound to class I MHC molecules, and brought to the surface of the cell by the class I MHC molecule, where they can be recognized by the T cell. If the TCR is specific for that antigen, it binds to the complex of the class I MHC molecule and the antigen, and the T cell destroys the cell. In order for the TCR to bind to the class I MHC molecule, the former must be accompanied by a glycoprote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fas Receptor
The Fas receptor, also known as Fas, FasR, apoptosis antigen 1 (APO-1 or APT), cluster of differentiation 95 (CD95) or tumor necrosis factor receptor superfamily member 6 (TNFRSF6), is a protein that in humans is encoded by the ''FAS'' gene. Fas was first identified using a monoclonal antibody generated by immunizing mice with the FS-7 cell line. Thus, the name Fas is derived from ''F''S-7-''a''ssociated ''s''urface antigen. The Fas receptor is a death receptor on the surface of cells that leads to programmed cell death ( apoptosis) if it binds its ligand, Fas ligand (FasL). It is one of two apoptosis pathways, the other being the mitochondrial pathway. Gene FAS receptor gene is located on the long arm of chromosome 10 (10q24.1) in humans and on chromosome 19 in mice. The gene lies on the plus ( Watson strand) and is 25,255 bases in length organized into nine protein encoding exons. Similar sequences related by evolution ( orthologs) are found in most mammals. Protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FLICE
Caspase-8 is a caspase protein, encoded by the ''CASP8'' gene. It most likely acts upon caspase-3. ''CASP8'' orthologs have been identified in numerous mammals for which complete genome data are available. These unique orthologs are also present in birds. Function The ''CASP8'' gene encodes a member of the cysteine-aspartic acid protease (caspase) family. Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis. Caspases exist as inactive proenzymes composed of a prodomain, a large protease subunit, and a small protease subunit. Activation of caspases requires proteolytic processing at conserved internal aspartic residues to generate a heterodimeric enzyme consisting of the large and small subunits. This protein is involved in the programmed cell death induced by Fas and various apoptotic stimuli. The N-terminal FADD-like death effector domain of this protein suggests that it may interact with Fas-interacting protein FADD. This protei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DcR3
Decoy receptor 3 (Dcr3), also known as tumor necrosis factor receptor superfamily member 6B (TNFRSF6B), TR6 and M68, is a soluble protein of the tumor necrosis factor receptor superfamily which inhibits Fas ligand-induced apoptosis. Discovery Dcr3 was identified in 1998 by the search of genes with homology to the TNFR gene superfamily in expressed sequence tag (EST) database. Structure The open reading frame of TNFRSF6B encodes 300 amino acids with a 29-residue signal sequence and four tandem cystein-rich repeats. Two transcript variants encoding the same isoform, but differing in the 5' UTR, have been observed for this gene. Unlike most of the other members of TNFR superfamily, TNFRSF6 is a soluble protein which contains no transmembrane domain. Function This gene belongs to the tumor necrosis factor receptor superfamily. It acts as a decoy receptor that competes with death receptors for ligand binding. The encoded protein is postulated to play a regulatory role in suppr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Death-inducing Signaling Complex
The death-inducing signaling complex or DISC is a multi-protein complex formed by members of the death receptor family of apoptosis-inducing cellular receptors. A typical example is FasR, which forms the DISC upon trimerization as a result of its ligand ( FasL) binding. The DISC is composed of the death receptor, FADD, and caspase 8. It transduces a downstream signal cascade resulting in apoptosis. Description The Fas ligands, or cytotoxicity-dependent APO-1-associated proteins, physically associate with APO-1 (also known as the Fas receptor, or CD95), a tumor necrosis factor containing a functional death domain. This association leads to the formation of the DISC, thereby inducing apoptosis. The entire process is initiated when the cell registers the presence of CD95L, the cognate ligand for APO-1. Upon binding, the CAP proteins and procaspase-8 (composed of FLICE, MACH, and Mch5) bind to CD95 through death domain and death effector domain interactions. Procaspase-8 activa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caspase-8
Caspase-8 is a caspase protein, encoded by the ''CASP8'' gene. It most likely acts upon caspase-3. ''CASP8'' orthologs have been identified in numerous mammals for which complete genome data are available. These unique orthologs are also present in birds. Function The ''CASP8'' gene encodes a member of the cysteine-aspartic acid protease (caspase) family. Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis. Caspases exist as inactive proenzymes composed of a prodomain, a large protease subunit, and a small protease subunit. Activation of caspases requires proteolytic processing at conserved internal aspartic residues to generate a heterodimeric enzyme consisting of the large and small subunits. This protein is involved in the programmed cell death induced by Fas and various apoptotic stimuli. The N-terminal FADD-like death effector domain of this protein suggests that it may interact with Fas-interacting protein FADD. This protei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Death Domain
Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain death is sometimes used as a legal definition of death. The remains of a former organism normally begin to decompose shortly after death. Death is an inevitable process that eventually occurs in almost all organisms. Death is generally applied to whole organisms; the similar process seen in individual components of an organism, such as cells or tissues, is necrosis. Something that is not considered an organism, such as a virus, can be physically destroyed but is not said to die. As of the early 21st century, over 150,000 humans die each day, with ageing being by far the most common cause of death. Many cultures and religions have the idea of an afterlife, and also may hold the idea of judgement of good and bad deeds in one's life (heave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Death Effector Domain
The death-effector domain (DED) is a protein interaction domain found only in eukaryotes that regulates a variety of cellular signalling pathways. The DED domain is found in inactive procaspases (cysteine proteases) and proteins that regulate caspase activation in the apoptosis cascade such as FAS-associating death domain-containing protein (FADD). FADD recruits procaspase 8 and procaspase 10 into a death induced signaling complex (DISC). This recruitment is mediated by a homotypic interaction between the procaspase DED and a second DED that is death effector domain in an adaptor protein that is directly associated with activated TNF receptors. Complex formation allows proteolytic activation of procaspase into the active caspase form which results in the initiation of apoptosis (cell death). Structurally the DED domain are a subclass of protein motif known as the death fold and contains 6 alpha helices, that closely resemble the structure of the Death domain (DD). Structure D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
