title: Functional interaction between FOXO3a and ATM regulates DNA damage response.
abstract: The maintenance of genomic stability in cells is relentlessly challenged by environmental stresses that induce DNA breaks, which activate the DNA-damage pathway mediated by ataxia-telangiectasia mutated (ATM) and its downstream mediators to control damage-induced cell-cycle checkpoints and DNA repair. Here, we show that FOXO3a interacts with ATM to promote phosphorylation of ATM at Ser 1981 and prompting its downstream mediators to form nuclear foci in response to DNA damage. Silencing FOXO3a in cells abrogates the formation of ATM-pS1981 and phospho-histone H2AX foci after DNA damage. Increasing FOXO3a in cells promotes ATM-regulated signalling, the intra-S-phase or G2-M cell-cycle checkpoints, and the repair of damaged DNA, whereas cells lacking FOXO3a did not trigger the DNA-repair mechanism after DNA damage. The carboxy-terminal domain of FOXO3a binds to the FAT domain of ATM, thereby contributing to the activation of ATM. These results suggest that ATM may be regulated directly by FOXO3a in the DNA-damage response.
authors.affiliation: Department of Molecular Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Tsai
authors.forename: Young Min
authors.initials: YM
authors.lastname: Chung
authors.forename: Yoko
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Xu
authors.forename: Mickey C-T
authors.initials: MC
authors.lastname: Hu
mesh_terms: D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D020552:Comet Assay; D004247:DNA / Q000378:metabolism / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011839:Radiation, Ionizing; D012694:Serine / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C499517:FOXO3 protein, human; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; C468783:H2AX protein, human; D006657:Histones; D025521:Tumor Suppressor Proteins; D012694:Serine; D004247:DNA; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases