Anti-Caspase-8 (Clone: ABM14C1)

Apoptosis occurs during normal cellular development and involves dramatic changes in cellular structure. Disruption of apoptosis may contribute to cancer as well as other autoimmune diseases. Caspase family of cysteine proteases has been shown to play a key role in apoptosis. Caspase-8 is a 55 kDa cytosolic protein that is synthesized as an inactive pro-enzyme. Activation of caspase-8 involves a two-step proteolysis: the cleavage of caspase-8 to generate a 43 kDa and a 12 kDa fragment which is further processed to 10 kDa. The p43 is then cleaved to yield p26 and the release of the active site containing p18. The Active/Cleaved Caspase-8 polyclonal antisera recognizes the large and small subunits of active/cleaved caspase-8. Whereas the antisera has a strong preference for active/cleaved caspase-8, in some cell or tissue systems or techniques the antisera may also recognize the proform of caspase-8 as well as intermediate caspase-8 cleavage fragments. Protein function: 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. [The UniProt Consortium]