title: Serine 249 phosphorylation by ATM protein kinase regulates hepatocyte nuclear factor-1α transactivation.
abstract: Hepatocyte nuclear factor-1 alpha (HNF1α) exerts important effects on gene expression in multiple tissues. Several studies have directly or indirectly supported the role of phosphorylation processes in the activity of HNF1α. However, the molecular mechanism of this phosphorylation remains largely unknown. Using microcapillary liquid chromatography MS/MS and biochemical assays, we identified a novel phosphorylation site in HNF1α at Ser249. We also found that the ATM protein kinase phosphorylated HNF1α at Ser249 in vitro in an ATM-dependent manner and that ATM inhibitor KU55933 treatment inhibited phosphorylation of HNF1α at Ser249 in vivo. Coimmunoprecipitation assays confirmed the association between HNF1α and ATM. Moreover, ATM enhanced HNF1α transcriptional activity in a dose-dependent manner, whereas the ATM kinase-inactive mutant did not. The use of KU55933 confirmed our observation. Compared with wild-type HNF1α, a mutation in Ser249 resulted in a pronounced decrease in HNF1α transactivation, whereas no dominant-negative effect was observed. The HNF1αSer249 mutant also exhibited normal nuclear localization but decreased DNA-binding activity. Accordingly, the functional studies of HNF1αSer249 mutant revealed a defect in glucose metabolism. Our results suggested that ATM regulates the activity of HNF1α by phosphorylation of serine 249, particularly in glucose metabolism, which provides valuable insights into the undiscovered mechanisms of ATM in the regulation of glucose homeostasis.
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing, 100850, China.
authors.forename: Long
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing, 100850, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, 102206, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing, 100850, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, 102206, China.
authors.forename: Yi-Qun
authors.initials: YQ
authors.lastname: Zhan
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing, 100850, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, 102206, China.
authors.forename: Chang-Yan
authors.initials: CY
authors.lastname: Li
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing, 100850, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, 102206, China.
authors.forename: Chang-Hui
authors.initials: CH
authors.lastname: Ge
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing, 100850, China.
authors.forename: Jian-Hong
authors.initials: JH
authors.lastname: Zhang
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing, 100850, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, 102206, China.
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Wang
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing, 100850, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, 102206, China. Electronic address: yumiaoer@hotmail.com.
authors.forename: Miao
authors.initials: M
authors.lastname: Yu
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing, 100850, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, 102206, China. Electronic address: xiaomingyang@sina.com.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Yang
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D004268:DNA-Binding Proteins; D005947:Glucose / Q000235:genetics / Q000378:metabolism*; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009025:Morpholines / Q000494:pharmacology; D009154:Mutation; D010766:Phosphorylation / Q000187:drug effects; D011401:Promoter Regions, Genetic; D011753:Pyrones / Q000494:pharmacology; D012694:Serine / Q000235:genetics; D015533:Transcriptional Activation / Q000187:drug effects / Q000235:genetics*
chemical_list: C495818:2-morpholin-4-yl-6-thianthren-1-yl-pyran-4-one; D004268:DNA-Binding Proteins; D051538:Hepatocyte Nuclear Factor 1-alpha; D009025:Morpholines; D011753:Pyrones; D012694:Serine; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D005947:Glucose
keywords: ATM; Glucose metabolism; HNF1α; Phosphorylation; Transcription regulation