Death effector domain (DED) found in caspase-8 (CASP8, FLICE), repeat 1. Caspases are aspartate-specific cysteine proteases with functions in apoptosis and immune signaling. Initiator caspases are the first to be activated following death- or inflammation-inducing signals. Caspase-8 is an initiator of death receptor mediated apoptosis. Together with FADD, caspase-10, and the pseudo-caspase c-FLIP, it forms the death-inducing signaling complex (DISC), whose formation is triggered by the activation of type 1 tumor necrosis factor (TNF) receptors such as Fas, TNF receptor 1, and TRAIL receptor. Caspase-8 also plays many important non-apoptotic functions including roles in embryonic development, cell adhesion and motility, immune cell proliferation and differentiation, T-cell activation, and NFkappaB signaling. It contains two N-terminal DED domains and a C-terminal caspase domain. DEDs comprise a subfamily of the Death Domain (DD) superfamily. DDs are protein-protein interaction domains found in a variety of domain architectures. Their common feature is that they form homodimers by self-association or heterodimers by associating with other members of the DD superfamily including PYRIN and CARD (Caspase activation and recruitment domain). They serve as adaptors in signaling pathways and can recruit other proteins into signaling complexes.
Comment:Based on the structure of the tandem DED domains of v-FLIP.
Comment:The tandem DED domains, DED1 and DED2, in FLIP are associated rigidly to form a single compact structure, with each domain playing a unique structural role and is not interchangeable with the other. This explains why both domains are required for FLIP function.
Jiyao W et al.(2023). "The conserved domain database in 2023.",