title: ATR-ATRIP kinase complex triggers activation of the Fanconi anemia DNA repair pathway.
abstract: ATR kinase activates the S-phase checkpoint when replication forks stall at sites of DNA damage. This event also causes phosphorylation of the Fanconi anemia (FA) protein FANCI, triggering its monoubiquitination of the key DNA repair factor FANCD2 by the FA core E3 ligase complex, thereby promoting this central pathway of DNA repair which permits replication to be restarted. However, the interplay between ATR and the FA pathway has been unclear. In this study, we present evidence that their action is directly linked, gaining insights into this relationship in a DT40 mutant cell line that is conditionally deficient in the critical ATR-binding partner protein ATRIP. Using this system, we showed that ATRIP was crucial for DNA damage-induced FANCD2 monoubiquitination and FANCI phosphorylation. ATR kinase phosphorylated recombinant FANCI protein in vitro, which was facilitated by the presence of FANCD2. Mechanistic investigations revealed that the RPA region but not the TopBP1 region of ATRIP was required for FANCD2 monoubiquitination, whereas Chk1 phosphorylation relied upon both domains. Together, our findings identify ATR as the kinase responsible for activating the FA pathway of DNA repair.
authors.affiliation: Laboratory of DNA Damage Signaling, Department of Late Effects Studies, Radiation Biology Center, Kyoto University, Kyoto, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shigechi
authors.forename: Junya
authors.initials: J
authors.lastname: Tomida
authors.forename: Koichi
authors.initials: K
authors.lastname: Sato
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: John K
authors.initials: JK
authors.lastname: Eykelenboom
authors.forename: Fabio
authors.initials: F
authors.lastname: Pessina
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Emi
authors.initials: E
authors.lastname: Uchida
authors.forename: Masamichi
authors.initials: M
authors.lastname: Ishiai
authors.forename: Noel F
authors.initials: NF
authors.lastname: Lowndes
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kurumizaka
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Maehara
authors.forename: Minoru
authors.initials: M
authors.lastname: Takata
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000502:physiology*; D002460:Cell Line; D002645:Chickens; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism*; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000378:metabolism; D051856:Fanconi Anemia Complementation Group Proteins / Q000378:metabolism*; D006801:Humans; D009154:Mutation; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D011994:Recombinant Proteins; D014162:Transfection
chemical_list: C521194:ATRIP protein, human; D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C519921:FANCI protein, human; D052236:Fanconi Anemia Complementation Group D2 Protein; D051856:Fanconi Anemia Complementation Group Proteins; D011994:Recombinant Proteins; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases