RIPK2, Active

RIPK2 (RIP2; RICK) is a death domain-containing protein kinase. Inohara identified cDNAs encoding a predicted 540-amino acid protein RICK, which contains an N-terminal serine/threonine kinase catalytic domain and a C-terminal caspase activation and recruitment domain. Inohara also demonstrated that RICK is a novel kinase that may regulate apoptosis induced by the FAS receptor pathway (1). McCarthy found that overexpression of RIP2 signaled both cell death and NF-kappa-B activation (2). Thome reported that RICK specifically interacted with the CARD of ICE/caspase-1, and this interaction correlated with the processing of pro-caspase-1 and the formation of the active caspase-1 p20 (3). Chin generated Ripk2-deficient mice and concluded that RIPK2 is implicated in the innate response to pathogens by NOD and TLR-induced cell signaling and mediates cytokine-induced Ifng production in Th1 and NK cells (4). Also Kobayashi demonstrated that RIPK2 is required for signaling through both TLR and NOD protein family members in the innate immune system as well as for appropriate TCR signaling in the adaptive immune response (5).