Caspase activation and recruitment domains (CARDs) found in IPS-1 and RIG-I-like RNA helicases
Caspase activation and recruitment domains (CARDs) found in IPS-1 (Interferon beta promoter stimulator protein 1) and Retinoic acid Inducible Gene I (RIG-I)-like DEAD box helicases. RIG-I-like helicases and IPS-1 play important roles in the induction of interferons in response to viral infection. They are crucial in triggering innate immunity and in developing adaptive immunity against viral pathogens. RIG-I-like helicases, including MDA5 and RIG-I, contain two N-terminal CARD domains and a C-terminal DEAD box RNA helicase domain. They are cytoplasmic RNA helicases that play an important role in host antiviral response by sensing incoming viral RNA. Upon activation, the signal is transferred to downstream pathways via the adaptor molecule IPS-1 (MAVS, VISA, CARDIF), leading to the induction of type I interferons. MDA5 and RIG-I associate with IPS-1 through a CARD-CARD interaction. In general, CARDs are death domains (DDs) found associated with caspases. They are known to be important in the signaling pathways for apoptosis, inflammation, and host-defense mechanisms. 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 DED (Death Effector Domain). They serve as adaptors in signaling pathways and can recruit other proteins into signaling complexes.
Jiyao W et al.(2023). "The conserved domain database in 2023.",