title: ATG16L1 phosphorylation is oppositely regulated by CSNK2/casein kinase 2 and PPP1/protein phosphatase 1 which determines the fate of cardiomyocytes during hypoxia/reoxygenation.
abstract: Recent studies have shown that the phosphorylation and dephosphorylation of ULK1 and ATG13 are related to autophagy activity. Although ATG16L1 is absolutely required for autophagy induction by affecting the formation of autophagosomes, the post-translational modification of ATG16L1 remains elusive. Here, we explored the regulatory mechanism and role of ATG16L1 phosphorylation for autophagy induction in cardiomyocytes. We showed that ATG16L1 was a phosphoprotein, because phosphorylation of ATG16L1 was detected in rat cardiomyocytes during hypoxia/reoxygenation (H/R). We not only demonstrated that CSNK2 (casein kinase 2) phosphorylated ATG16L1, but also identified the highly conserved Ser139 as the critical phosphorylation residue for CSNK2. We further established that ATG16L1 associated with the ATG12-ATG5 complex in a Ser139 phosphorylation-dependent manner. In agreement with this finding, CSNK2 inhibitor disrupted the ATG12-ATG5-ATG16L1 complex. Importantly, phosphorylation of ATG16L1 on Ser139 was responsible for H/R-induced autophagy in cardiomyocytes, which protects cardiomyocytes from apoptosis. Conversely, we determined that wild-type PPP1 (protein phosphatase 1), but not the inactive mutant, associated with ATG16L1 and antagonized CSNK2-mediated phosphorylation of ATG16L1. Interestingly, one RVxF consensus site for PPP1 binding in the C-terminal tail of ATG16L1 was identified; mutation of this site disrupted its association with ATG16L1. Notably, CSNK2 also associated with PPP1, but ATG16L1 depletion impaired the interaction between CSNK2 and PPP1. Collectively, these data identify ATG16L1 as a bona fide physiological CSNK2 and PPP1 substrate, which reveals a novel molecular link from CSNK2 to activation of the autophagy-specific ATG12-ATG5-ATG16L1 complex and autophagy induction.
authors.affiliation: a Department of Cardiology ; Affiliated Baoan Hospital of Southern Medical University ; Shenzhen , China.
authors.forename: Huiwen
authors.initials: H
authors.lastname: Song
authors.forename: Jun
authors.initials: J
authors.lastname: Pu
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Lihua
authors.initials: L
authors.lastname: Wu
authors.forename: Jianmin
authors.initials: J
authors.lastname: Xiao
authors.forename: Qigong
authors.initials: Q
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Mingke
authors.initials: M
authors.lastname: Ni
authors.forename: Jinggang
authors.initials: J
authors.lastname: Mo
authors.forename: Yunliang
authors.initials: Y
authors.lastname: Zheng
authors.forename: Deli
authors.initials: D
authors.lastname: Wan
authors.forename: XiongJiu
authors.initials: X
authors.lastname: Cai
authors.forename: Yaping
authors.initials: Y
authors.lastname: Cao
authors.forename: Weiyi
authors.initials: W
authors.lastname: Xiao
authors.forename: Lei
authors.initials: L
authors.lastname: Ye
authors.forename: Enyuan
authors.initials: E
authors.lastname: Tu
authors.forename: Zhihai
authors.initials: Z
authors.lastname: Lin
authors.forename: Jianxin
authors.initials: J
authors.lastname: Wen
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Lu
authors.forename: Jian
authors.initials: J
authors.lastname: He
authors.forename: Yi
authors.initials: Y
authors.lastname: Peng
authors.forename: Jing
authors.initials: J
authors.lastname: Su
authors.forename: Heng
authors.initials: H
authors.lastname: Zhang
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Meihua
authors.initials: M
authors.lastname: Lin
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001343:Autophagy; D000071187:Autophagy-Related Protein 5; D000071183:Autophagy-Related Proteins; D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism*; D047390:Casein Kinase II / Q000378:metabolism; D015687:Cell Hypoxia; D019070:Cell Lineage; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D032383:Myocytes, Cardiac / Q000166:cytology*; D010100:Oxygen / Q000737:chemistry; D010766:Phosphorylation; D011485:Protein Binding; D054645:Protein Phosphatase 1 / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D015427:Reperfusion Injury; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000737:chemistry
chemical_list: C518959:ATG16L1 protein, human; C502778:ATG5 protein, human; D000071187:Autophagy-Related Protein 5; D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins; D008869:Microtubule-Associated Proteins; D011994:Recombinant Proteins; D012694:Serine; C570325:CSNK2A1 protein, human; D047390:Casein Kinase II; C517187:PPP1CA protein, human; D054645:Protein Phosphatase 1; D010100:Oxygen
keywords: ATG16L1; autophagy; cardiomyocyte; casein kinase 2; protein phosphatase 1