CRADD, a novel human apoptotic adaptor molecule for caspase-2, and FasL/tumor necrosis factor receptor-interacting protein RIP

FADD/MORT1 is a death domain (DD)-containing adaptor/signaling molecule that interacts with the intracellular DD of FAS/APO-I (CD95) and tumor necrosis factor receptor 1 and the prodomain of Caspase-8 (Mch5/MACH/FLICE). FADD engagement of Caspase-8 presumably activates this Caspase and leads to Apoptosis. Another DD-containing adaptor/signaling molecule, CRADD, was identified and was shown to induce Apoptosis. CRADD has a dual-domain structure similar to that of FADD. It has an NH2-terminal Caspase homology domain that interacts with caspase-2 and a COOH-terminal DD that interacts with RIP. CRADD is constitutively expressed in many tissues and thus could play a role in regulating Apoptosis in mammalian cells.