期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：4
页码：1962-1970
DOI：10.1073/pnas.1917112117
出版社：The National Academy of Sciences of the United States of America
摘要：Necroptosis is a regulated necrotic cell death pathway, mediated by a supermolecular complex called the necrosome, which contains receptor-interacting protein kinase 1 and 3 (RIPK1, RIPK3) and mixed-lineage kinase domain-like protein (MLKL). Phosphorylation of human RIPK3 at serine 227 (S227) has been shown to be required for downstream MLKL binding and necroptosis progression. Tandem immunoprecipitation of RIPK3 reveals that casein kinase 1 (CK1) family proteins associate with the necrosome upon necroptosis induction, and this interaction depends on the kinase activity of RIPK3. In addition, CK1 proteins colocalize with RIPK3 puncta during necroptosis. Importantly, CK1 proteins directly phosphorylate RIPK3 at S227 in vitro and in vivo. Loss of CK1 proteins abolishes S227 phosphorylation and blocks necroptosis. Furthermore, a RIPK3 mutant with mutations in the CK1 recognition motif fails to be phosphorylated at S227, does not bind or phosphorylate MLKL, and is unable to activate necroptosis. These results strongly suggest that CK1 proteins are necrosome components which are responsible for RIPK3-S227 phosphorylation.
