Chk1-mediated phosphorylation of FANCE is required for the Fanconi anemia/BRCA pathway.
The eleven Fanconi anemia (FA) proteins cooperate in a novel pathway required for the repair of DNA cross-links. Eight of the FA proteins (A, B, C, E, F, G, L, and M) form a core enzyme complex, required for the monoubiquitination of FANCD2 and the assembly of FANCD2 nuclear foci. Here, we show that, in response to DNA damage, Chk1 directly phosphorylates the FANCE subunit of the FA core complex on two conserved sites (threonine 346 and serine 374). Phosphorylated FANCE assembles in nuclear foci and colocalizes with FANCD2. A nonphosphorylated mutant form of FANCE (FANCE-T346A/S374A), when expressed in a FANCE-deficient cell line, allows FANCD2 monoubiquitination, FANCD2 foci assembly, and normal S-phase progression. However, the mutant FANCE protein fails to complement the mitomycin C hypersensitivity of the transfected cells. Taken together, these results elucidate a novel role of Chk1 in the regulation of the FA/BRCA pathway and in DNA cross-link repair. Chk1-mediated phosphorylation of FANCE is required for a function independent of FANCD2 monoubiquitination.
Wang
Xiaozhe
X
Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA 02115, USA.
Kennedy
Richard D
RD
Ray
Kallol
K
Stuckert
Patricia
P
Ellenberger
Tom
T
D'Andrea
Alan D
AD
D000595:Amino Acid Sequence; D019313:BRCA1 Protein / Q000378:metabolism*; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D000071877:Checkpoint Kinase 1; D017124:Conserved Sequence; D004249:DNA Damage; D004261:DNA Replication / Q000187:drug effects; D004351:Drug Resistance / Q000187:drug effects; D005199:Fanconi Anemia / Q000378:metabolism*; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000378:metabolism; D052239:Fanconi Anemia Complementation Group E Protein / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D016685:Mitomycin / Q000494:pharmacology; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D034741:RNA, Small Interfering / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism
D019313:BRCA1 Protein; D052236:Fanconi Anemia Complementation Group D2 Protein; D052239:Fanconi Anemia Complementation Group E Protein; D050505:Mutant Proteins; D034741:RNA, Small Interfering; D025801:Ubiquitin; D016685:Mitomycin; D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1