Background：

Serine-threonine kinase which transduces inflammatory and cell-death signals 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. Phosphorylates DAB2IP at ’Ser-728’ in a TNF-alpha-dependent manner， and thereby activates the MAP3K5-JNK apoptotic cascade. 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