RIP4 Antibody #12636

The receptor-interacting protein (RIP) family of serine-threonine kinases (RIP, RIP2, RIP3, and RIP4) are important regulators of cellular stress that trigger pro-survival and inflammatory responses through the activation of NF-κB, as well as pro-apoptotic pathways (1). In addition to the kinase domain, RIP contains a death domain responsible for interaction with the death domain receptor Fas and recruitment to TNF-R1 through interaction with TRADD (2,3). RIP-deficient cells show a failure in TNF-mediated NF-κB activation, making the cells more sensitive to apoptosis (4,5). RIP also interacts with TNF-receptor-associated factors (TRAFs) and can recruit IKKs to the TNF-R1 signaling complex via interaction with NEMO, leading to IκB phosphorylation and degradation (6,7). Overexpression of RIP induces both NF-κB activation and apoptosis (2,3). Caspase-8-dependent cleavage of the RIP death domain can trigger the apoptotic activity of RIP (8).
Receptor-interacting serine-threonine kinase 4 (RIP4, ANKRD3, DIK, PKK, or RIPK4) is a membrane-associated, ankyrin repeat-containing member of the RIP family first identified in HaCat cells (9,10). RIP4 has been shown to be involved in keratinocyte differentiation in vivo as well as wound repair (11-13). Studies indicate that siRNA knockdown of RIP4 in human xenografted tumor cells suppresses Wnt-dependent growth while over-expression of RIP4 in vitro stabilized β-catenin and lead to an increase in Wnt-dependent gene expression (14).