title: An ATR- and BRCA1-mediated Fanconi anemia pathway is required for activating the G2/M checkpoint and DNA damage repair upon rereplication.
abstract: The timely assembly of prereplicative complexes at replication origins is tightly controlled to ensure that genomic DNA is replicated once per cell cycle. The loss of geminin, a DNA replication inhibitor, causes rereplication that activates a G2/M checkpoint in human cancer cells. Fanconi anemia (FA) is an autosomal recessive and X-linked disorder associated with cancer susceptibility. Here we show that rereplication activates the FA pathway both for the activation of a G2/M checkpoint and for repair processes, like recruitment of RAD51. Both ATR and BRCA1 are required to activate the FA pathway. The G2/M checkpoint-mediated arrest of the cell cycle is critical for the prevention of both apoptosis and the accumulation of cells with rereplicated DNA, because the loss of ATR, BRCA1, or FANCA promotes apoptosis and suppresses the accumulation. The accumulation of cells with rereplicated DNA is restored by the artificial induction of a G2-phase arrest even when ATR, BRCA1, or FANCA is absent. Therefore, the ATR- and BRCA1-mediated FA pathway is required for the activation of a G2/M checkpoint and for DNA damage repair in response to the endogenous signal of rereplication. In its absence, the cells rapidly lose viability when faced with rereplication.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Box 800733, Jordan Hall 1240, 1300 Jefferson Park Avenue, Charlottesville, VA 22908, USA.
authors.forename: Wenge
authors.initials: W
authors.lastname: Zhu
authors.forename: Anindya
authors.initials: A
authors.lastname: Dutta
mesh_terms: D017209:Apoptosis; D064007:Ataxia Telangiectasia Mutated Proteins; D019313:BRCA1 Protein / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D004249:DNA Damage; D004260:DNA Repair; D004261:DNA Replication; D005199:Fanconi Anemia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D052217:Fanconi Anemia Complementation Group A Protein / Q000235:genetics / Q000378:metabolism; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000378:metabolism; D064248:Geminin; D006801:Humans; D008954:Models, Biological; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D051135:Rad51 Recombinase / Q000378:metabolism
chemical_list: D019313:BRCA1 Protein; D018797:Cell Cycle Proteins; C498471:FANCA protein, human; C499905:FANCD2 protein, human; D052217:Fanconi Anemia Complementation Group A Protein; D052236:Fanconi Anemia Complementation Group D2 Protein; C577995:GMNN protein, human; D064248:Geminin; D034741:RNA, Small Interfering; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; C495153:RAD51 protein, human; D051135:Rad51 Recombinase