The Gβy-Src signaling pathway regulates TNF-induced necroptosis via control of necrosome translocation

Formation of multi-component signaling complex necrosomes is essential for tumor necrosis factor a （TNF）-induced programmed necrosis （also called necroptosis）. However, the mechanisms of necroptosis are still largely unknown. We isolated a TNF-resistant L929 mutant cell line generated by insertion and identified that disruption of the guanine nucleotide-binding protein y 10 （GTlO） gene is responsible for this phenotype. We further show that Gyl0 is involved in TNF-induced necroptosis and Gβ2 is the partner of Cyl0. Src is the downstream effector of Gβ710 in TNF-induced necroptosis because TNF-induced Src activation was impaired upon Gy10 knockdown. Gy10 does not affect TNF-induced activation of NF-KB and MAPKs and the formation of necrosomes, but is required for trafficking of necrosomes to their potential functioning site, an unidentified subcellular organelle that can be fractionated into heterotypic membrane fractions. The TNF-induced Gβy-Src signaling pathway is independent of RIP1/RIP3 kinase activity and necrosome formation, but is required for the necrosome to function.