title: Cdk1 uncouples CtIP-dependent resection and Rad51 filament formation during M-phase double-strand break repair.
abstract: DNA double-strand break (DSB) resection, which results in RPA-bound single-stranded DNA (ssDNA), is activated in S phase by Cdk2. RPA-ssDNA activates the ATR-dependent checkpoint and homology-directed repair (HDR) via Rad51-dependent mechanisms. On the other hand, the fate of DSBs sustained during vertebrate M phase is largely unknown. We use cell-free Xenopus laevis egg extracts to examine the recruitment of proteins to chromatin after DSB formation. We find that S-phase extract recapitulates a two-step resection mechanism. M-phase chromosomes are also resected in cell-free extracts and cultured human cells. In contrast to the events in S phase, M-phase resection is solely dependent on MRN-CtIP. Despite generation of RPA-ssDNA, M-phase resection does not lead to ATR activation or Rad51 chromatin association. Remarkably, we find that Cdk1 permits resection by phosphorylation of CtIP but also prevents Rad51 binding to the resected ends. We have thus identified Cdk1 as a critical regulator of DSB repair in M phase. Cdk1 induces persistent ssDNA-RPA overhangs in M phase, thereby preventing both classical NHEJ and Rad51-dependent HDR.
authors: Institute for Cancer Genetics, Columbia University Medical Center, New York, NY 10032, USA.
authors: Shaun E
authors: SE
authors: Peterson
authors: Yinyin
authors: Y
authors: Li
authors: Brian T
authors: BT
authors: Chait
authors: Max E
authors: ME
authors: Gottesman
authors: Richard
authors: R
authors: Baer
authors: Jean
authors: J
authors: Gautier
mesh_terms: D000818:Animals; D034961:Antigens, Nuclear / Q000378:metabolism; D064007:Ataxia Telangiectasia Mutated Proteins; D016203:CDC2 Protein Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism; D002455:Cell Division / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D002474:Cell-Free System; D000071877:Checkpoint Kinase 1; D002843:Chromatin / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D053903:DNA Breaks, Double-Stranded; D004265:DNA Helicases / Q000378:metabolism; D004260:DNA Repair / Q000502:physiology*; D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004720:Endonucleases / Q000378:metabolism; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D000072200:Ku Autoantigen; D000076228:MRE11 Homologue Protein; D008540:Meiosis / Q000502:physiology; D008938:Mitosis / Q000502:physiology; D009685:Nuclear Envelope / Q000502:physiology; D010063:Ovum; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051135:Rad51 Recombinase / Q000378:metabolism*; D053484:RecQ Helicases / Q000378:metabolism; D051716:Replication Protein A / Q000378:metabolism; D016196:S Phase / Q000502:physiology; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D000071657:Werner Syndrome Helicase; D029867:Xenopus Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D034961:Antigens, Nuclear; D018797:Cell Cycle Proteins; D002843:Chromatin; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D006657:Histones; C510917:Mre11 protein, Xenopus; D047428:Protein Kinase Inhibitors; C559071:RBBP8 protein, Xenopus; D051716:Replication Protein A; D025521:Tumor Suppressor Proteins; D029867:Xenopus Proteins; D011494:Protein Kinases; C576898:Atr protein, Xenopus; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D000071877:Checkpoint Kinase 1; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; C495891:Cdk2 protein, Xenopus; D051357:Cyclin-Dependent Kinase 2; C495152:RAD51 protein, Xenopus; D051135:Rad51 Recombinase; D004720:Endonucleases; D000076228:MRE11 Homologue Protein; C097151:Bloom syndrome protein; D004265:DNA Helicases; C533186:DNA2 protein, Xenopus; D053484:RecQ Helicases; D000071657:Werner Syndrome Helicase; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen; C507159:WRN protein, Xenopus