Caspase-8 (CASP8) Antibody – Polyclonal

This gene is part of a family of caspases, aspartate-specific cysteine proteases well studied for their involvement in immune and apoptosis signaling. This protein, an initiator of apoptotic cell death, is activated by death-inducing tumor necrosis family receptors and targets downstream effectors. In mouse deficiency of this gene can cause embryonic lethality. This protein may have a role in embryogenesis. Alternative splicing results in multiple transcript variants that encode different protein isoforms. [provided by RefSeq, Apr 2013]

CASP8: Most upstream protease of the activation cascade of caspases responsible for the TNFRSF6/FAS mediated and TNFRSF1A induced cell death. Binding to the adapter molecule FADD recruits it to either receptor. The resulting aggregate called death- inducing signaling complex (DISC) performs CASP8 proteolytic activation. The active dimeric enzyme is then liberated from the DISC and free to activate downstream apoptotic proteases. Proteolytic fragments of the N-terminal propeptide (termed CAP3, CAP5 and CAP6) are likely retained in the DISC. Cleaves and activates CASP3, CASP4, CASP6, CASP7, CASP9 and CASP10. May participate in the GZMB apoptotic pathways. Cleaves ADPRT. Hydrolyzes the small-molecule substrate, Ac-Asp-Glu-Val-Asp-|-AMC. Likely target for the cowpox virus CRMA death inhibitory protein. Isoform 5, isoform 6, isoform 7 and isoform 8 lack the catalytic site and may interfere with the pro-apoptotic activity of the complex. Heterotetramer that consists of two anti-parallel arranged heterodimers, each one formed by a 18 kDa (p18) and a 10 kDa (p10) subunit. Interacts with FADD, CFLAR and PEA15. Isoform 9 interacts at the endoplasmic reticulum with a complex containing BCAP31, BAP29, BCL2 and/or BCL2L1. Interacts with TNFAIP8L2. Interacts with human cytomegalovirus/HHV-5 protein vICA/UL36; this interaction inhibits CASP8 activation. Isoform 1, isoform 5 and isoform 7 are expressed in a wide variety of tissues. Highest expression in peripheral blood leukocytes, spleen, thymus and liver. Barely detectable in brain, testis and skeletal muscle. Belongs to the peptidase C14A family. 9 isoforms of the human protein are produced by alternative splicing.

Protein type: Protease; EC 3.4.22.61; Apoptosis

Cellular Component: CD95 death-inducing signaling complex; cytoplasm; cytosol; lipid raft; microtubule organizing center; mitochondrion; neuron projection; Noc1p-Noc2p complex; nucleoplasm; nucleus; plasma membrane; protein complex

Molecular Function: cysteine-type endopeptidase activity; cysteine-type peptidase activity; death receptor binding; endopeptidase activity; hydrolase activity; peptidase activity; protein binding; protein complex binding; protein heterodimerization activity; tumor necrosis factor receptor binding; ubiquitin protein ligase binding

Biological Process: angiogenesis; apoptosis; cardiac muscle development; caspase activation; heart development; induction of apoptosis via death domain receptors; macrophage differentiation; negative regulation of I-kappaB kinase/NF-kappaB cascade; neural tube formation; positive regulation of I-kappaB kinase/NF-kappaB cascade; positive regulation of macrophage differentiation; positive regulation of proteolysis; protein heterooligomerization; proteolysis; proteolysis involved in cellular protein catabolic process; regulation of apoptosis; response to ethanol