biostudies-literatureWu GChinese Academy of SciencesScience and Technology Commission of Shanghai MunicipalityChinese Academy of Sciences (CAS)National Natural Science Foundation of ChinaScience and Technology Commission of Shanghai Municipality (Shanghai Municipal Science and Technology Commission)National Natural Science Foundation of China (National Science Foundation of China)773https://www.ebi.ac.uk/biostudies/studies/S-EPMC9452587biostudies-literatureUnknown13(9)Activation of TNFR1 by TNFα induces the formation of a membrane-associated, intracellular complex termed complex I. Complex I orchestrates a complex pattern of modifications on key regulators of TNF signaling that collectively determines the cell fate by activating pro-survival or executing cell death programs. However, the regulatory mechanism of complex I in cell-fate decision is not fully understood. Here we identify protein phosphatase-6 (PP6) as a previously unidentified component of complex I. Loss of PP6 protects cells from TNFα-mediated cell death. The role of PP6 in regulating cell death requires its phosphatase activity and regulatory subunits. Further mechanistic studies show that PP6 modulates LUBAC-mediated M1-ubiquitination of RIPK1 and c-FLIP_L to promote RIPK1 actCell death & diseasePP6 negatively modulates LUBAC-mediated M1-ubiquitination of RIPK1 and c-FLIP_L to promote TNFα-mediated cell death.PMC945258792049303XDB39030200321707552183700418JC1420500918492042019SHZDZX0231801163Li YLiang WLi DXie XLu XZhang MSun WTong YWu GShan BYuan JfalsePP6 negatively modulates LUBAC-mediated M1-ubiquitination of RIPK1 and c-FLIP_L to promote TNFα-mediated cell death.Activation of TNFR1 by TNFα induces the formation of a membrane-associated, intracellular complex termed complex I. Complex I orchestrates a complex pattern of modifications on key regulators of TNF signaling that collectively determines the cell fate by activating pro-survival or executing cell death programs. However, the regulatory mechanism of complex I in cell-fate decision is not fully understood. Here we identify protein phosphatase-6 (PP6) as a previously unidentified component of complex I. Loss of PP6 protects cells from TNFα-mediated cell death. The role of PP6 in regulating cell death requires its phosphatase activity and regulatory subunits. Further mechanistic studies show that PP6 modulates LUBAC-mediated M1-ubiquitination of RIPK1 and c-FLIP_L to promote RIPK1 act2022-01-01T00:00:00Z2022 Sep2025-04-18T18:24:15.662Z2025-04-07T06:00:15.395ZS-EPMC94525873607104010.1038/s41419-022-05206-9