Essential adapter molecule for the activation of NF-kappa-B. Following different upstream signals (binding of inflammatory cytokines, stimulation of pathogen recognition receptors, or DNA damage), particular RIPK1-containing complexes are formed, initiating a limited number of cellular responses. Upon TNFA stimulation RIPK1 is recruited to a TRADD-TRAF complex initiated by TNFR1 trimerization. There, it is ubiquitinated via 'Lys-63'-link chains, inducing its association with the IKK complex, and its activation through NEMO binding of polyubiquitin chains.
Interacts (via RIP homotypic interaction motif) with RIPK3 (via RIP homotypic interaction motif); this interaction induces RIPK1 necroptosis-specific phosphorylation, formation of the necroptosis-inducing complex. Interacts (via the death domain) with TNFRSF6 (via the death domain) and TRADD (via the death domain). Is recruited by TRADD to TNFRSF1A in a TNF-dependent process. Binds RNF216, EGFR, IKBKG, TRAF1, TRAF2 and TRAF3. Interacts with BNLF1. Interacts with SQSTM1 upon TNF-alpha stimulation. May interact with MAVS/IPS1. Interacts with ZFAND5. Interacts with RBCK.
亚细胞定位
Cytoplasm. Cell membrane.
组织特异性
Expressed ubiquitously but at low levels. Shows a strong expression in the erythrocytes.
翻译后修饰
Proteolytically cleaved by caspase-8 during TNF-induced apoptosis. Cleavage abolishes NF-kappa-B activation and enhances pro-apototic signaling through the TRADD-FADD interaction.
RIPK1 and RIPK3 undergo reciprocal auto- and trans-phosphorylation. Phosphorylation of Ser-161 by RIPK3 is necessary for the formation of the necroptosis-inducing complex.
Ubiquitinated by 'Lys-11'-, 'Lys-48'-, 'Lys-63'- and linear-linked type ubiquitin. Polyubiquitination with 'Lys-63'-linked chains by TRAF2 induces association with the IKK complex. Deubiquitination of 'Lys-63'-linked chains and polyubiquitination with 'Lys-48'-linked chains by TNFAIP3 leads to RIPK1 proteasomal degradation and consequently downregulates TNF-alpha-induced NFkappa-B signaling. Linear polyubiquitinated; the head-to-tail polyubiquitination is mediated by the LUBAC complex. LPS-mediated activation of NF-kappa-B. Also ubiquitinated with 'Lys-11'-linked chains.
相似性
Belongs to the protein kinase superfamily. TKL Ser/Thr protein kinase family. Contains 1 death domain.
Contains 1 protein kinase domain.
功能
Serine-threonine kinase which transduces inflammatory and cell-death signals (necroptosis) following death receptors ligation, activation of pathogen recognition receptors (PRRs), and DNA damage. Upon activation of TNFR1 by the TNF-alpha family cytokines, TRADD and TRAF2 are recruited to the receptor. Ubiquitination by TRAF2 via 'Lys-63'-link chains acts as a critical enhancer of communication with downstream signal transducers in the mitogen-activated protein kinase pathway and the NF-kappa-B pathway, which in turn mediate downstream events including the activation of genes encoding inflammatory molecules. Polyubiquitinated protein binds to IKBKG/NEMO, the regulatory subunit of the IKK complex, a critical event for NF-kappa-B activation. Interaction with other cellular RHIM-containing adapters initiates gene activation and cell death. RIPK1 and RIPK3 association, in particular, forms a necroptosis-inducing complex.