RIPK1(Receptor-interacting serine/threonine-protein kinase 1) is primarily involved in mediating TNF-R1-induced cell activation, apoptosis and necroptosis and belongs to a novel class of kinases thatfunction in cell survival and cell death mechanisms.TRADD (TNF-R1-associated death domain) and FADD (FAS-associated death domain) associate with the death domains of both FAS and TNF-R1 via their DDH regions. Overexpression of TRADD leads to NFκB activation and apoptosis in the absence of TNF.Overexpression of FADD causes apoptosis, which can be blocked by the bovine pox protein CrmA, suggesting that FADD lies upstream of ICE and possibly other serine proteases.
