title: ATR-dependent phosphorylation of FANCM at serine 1045 is essential for FANCM functions.
abstract: Fanconi anemia (FA) is a genome instability syndrome that has been associated with both cancer predisposition and bone marrow failure. FA proteins are involved in cellular response to replication stress in which they coordinate DNA repair with DNA replication and cell-cycle progression. One regulator of the replication stress response is the ATP-dependent DNA translocase FANCM, which we have shown to be hyperphosphorylated in response to various genotoxic agents. However, the significance of this phosphorylation remained unclear. Here, we show that genotoxic stress-induced FANCM phosphorylation is ATR-dependent and that this modification is highly significant for the cellular response to replication stress. We identified serine (S1045) residue of FANCM that is phosphorylated in response to genotoxic stress and this effect is ATR-dependent. We show that S1045 is required for FANCM functions including its role in FA pathway integrity, recruiting FANCM to the site of interstrand cross links, preventing the cells from entering mitosis prematurely, and efficient activation of the CHK1 and G2-M checkpoints. Overall, our data suggest that an ATR-FANCM feedback loop is present in the FA and replication stress response pathways and that it is required for both efficient ATR/CHK1 checkpoint activation and FANCM function.
authors.affiliation: Division of Experimental Hematology & Cancer Biology and Cancer & Blood Diseases Institute, Cincinnati Children's Hospital Medical Center; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA.
authors.forename: Thiyam Ramsing
authors.initials: TR
authors.lastname: Singh
authors.forename: Abdullah Mahmood
authors.initials: AM
authors.lastname: Ali
authors.forename: Manikandan
authors.initials: M
authors.lastname: Paramasivam
authors.forename: Arun
authors.initials: A
authors.lastname: Pradhan
authors.forename: Kebola
authors.initials: K
authors.lastname: Wahengbam
authors.forename: Michael M
authors.initials: MM
authors.lastname: Seidman
authors.forename: Amom Ruhikanta
authors.initials: AR
authors.lastname: Meetei
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D045744:Cell Line, Tumor; D000071877:Checkpoint Kinase 1; D004265:DNA Helicases / Q000235:genetics* / Q000378:metabolism*; D004261:DNA Replication; D005199:Fanconi Anemia / Q000235:genetics / Q000378:metabolism; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000235:genetics / Q000378:metabolism; D016195:G2 Phase / Q000502:physiology; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis / Q000235:genetics; D009154:Mutation; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: C499905:FANCD2 protein, human; D052236:Fanconi Anemia Complementation Group D2 Protein; D012694:Serine; D011494:Protein Kinases; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; C518295:FANCM protein, human; D004265:DNA Helicases