TY - JOUR
T1 - RIPK1 dephosphorylation and kinase activation by PPP1R3G/PP1γ promote apoptosis and necroptosis
AU - Du, Jingchun
AU - Xiang, Yougui
AU - Liu, Hua
AU - Liu, Shuzhen
AU - Kumar, Ashwani
AU - Xing, Chao
AU - Wang, Zhigao
N1 - Funding Information:
We would like to thank Dr. Zhijian “James” Chen, Dr. Youtong Wu, Dr. Chee-Kwee Ea for helping with the CRISPR screen as well as reagents and critical discussions. Thanks to Dr. Eric Olson and John McAnally for generating the knockout mice. Thanks to Dr. Pascal Meier for phospho-S320-RIPK1 antibody. Thanks to Hong Yu, Dr. Mohammad Goodarzi, and Dr. Andrew Lemoff at the UT Southwestern Proteomics Core, Dr. Bret Evers, and John Shelton at the UT Southwestern Histo Pathology Core for excellent technical assistance. Thanks to Dr. Rhonda Bassel-Duby and Dr. Thomas Carroll for the critical reading of the manuscript. This work is supported by grants from the Welch Foundation (I1827) and NIGMS (R01, GM120502) to Z.W. Z.W. is the Virginia Murchison Linthicum Scholar in Medical Research, and Cancer Prevention and Research Institute of Texas Scholar (R1222).
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - Receptor-interacting protein kinase 1 (RIPK1) is a key regulator of inflammation and cell death. Many sites on RIPK1, including serine 25, are phosphorylated to inhibit its kinase activity and cell death. How these inhibitory phosphorylation sites are dephosphorylated is poorly understood. Using a sensitized CRISPR whole-genome knockout screen, we discover that protein phosphatase 1 regulatory subunit 3G (PPP1R3G) is required for RIPK1-dependent apoptosis and type I necroptosis. Mechanistically, PPP1R3G recruits its catalytic subunit protein phosphatase 1 gamma (PP1γ) to complex I to remove inhibitory phosphorylations of RIPK1. A PPP1R3G mutant which does not bind PP1γ fails to rescue RIPK1 activation and cell death. Furthermore, chemical prevention of RIPK1 inhibitory phosphorylations or mutation of serine 25 of RIPK1 to alanine largely restores cell death in PPP1R3G-knockout cells. Finally, Ppp1r3g−/− mice are protected from tumor necrosis factor-induced systemic inflammatory response syndrome, confirming the important role of PPP1R3G in regulating apoptosis and necroptosis in vivo.
AB - Receptor-interacting protein kinase 1 (RIPK1) is a key regulator of inflammation and cell death. Many sites on RIPK1, including serine 25, are phosphorylated to inhibit its kinase activity and cell death. How these inhibitory phosphorylation sites are dephosphorylated is poorly understood. Using a sensitized CRISPR whole-genome knockout screen, we discover that protein phosphatase 1 regulatory subunit 3G (PPP1R3G) is required for RIPK1-dependent apoptosis and type I necroptosis. Mechanistically, PPP1R3G recruits its catalytic subunit protein phosphatase 1 gamma (PP1γ) to complex I to remove inhibitory phosphorylations of RIPK1. A PPP1R3G mutant which does not bind PP1γ fails to rescue RIPK1 activation and cell death. Furthermore, chemical prevention of RIPK1 inhibitory phosphorylations or mutation of serine 25 of RIPK1 to alanine largely restores cell death in PPP1R3G-knockout cells. Finally, Ppp1r3g−/− mice are protected from tumor necrosis factor-induced systemic inflammatory response syndrome, confirming the important role of PPP1R3G in regulating apoptosis and necroptosis in vivo.
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U2 - 10.1038/s41467-021-27367-5
DO - 10.1038/s41467-021-27367-5
M3 - Article
C2 - 34862394
AN - SCOPUS:85120856114
SN - 2041-1723
VL - 12
JO - Nature communications
JF - Nature communications
IS - 1
M1 - 7067
ER -