title: Polo-like kinase 3 regulates CtIP during DNA double-strand break repair in G1.
abstract: DNA double-strand breaks (DSBs) are repaired by nonhomologous end joining (NHEJ) or homologous recombination (HR). The C terminal binding protein-interacting protein (CtIP) is phosphorylated in G2 by cyclin-dependent kinases to initiate resection and promote HR. CtIP also exerts functions during NHEJ, although the mechanism phosphorylating CtIP in G1 is unknown. In this paper, we identify Plk3 (Polo-like kinase 3) as a novel DSB response factor that phosphorylates CtIP in G1 in a damage-inducible manner and impacts on various cellular processes in G1. First, Plk3 and CtIP enhance the formation of ionizing radiation-induced translocations; second, they promote large-scale genomic deletions from restriction enzyme-induced DSBs; third, they are required for resection and repair of complex DSBs; and finally, they regulate alternative NHEJ processes in Ku(-/-) mutants. We show that mutating CtIP at S327 or T847 to nonphosphorylatable alanine phenocopies Plk3 or CtIP loss. Plk3 binds to CtIP phosphorylated at S327 via its Polo box domains, which is necessary for robust damage-induced CtIP phosphorylation at S327 and subsequent CtIP phosphorylation at T847.
authors.affiliation: Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
authors.forename: Olivia
authors.initials: O
authors.lastname: Barton
authors.affiliation: Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
authors.forename: Steffen C
authors.initials: SC
authors.lastname: Naumann
authors.affiliation: Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
authors.forename: Ronja
authors.initials: R
authors.lastname: Diemer-Biehs
authors.affiliation: Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Künzel
authors.affiliation: Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Steinlage
authors.affiliation: Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
authors.forename: Sandro
authors.initials: S
authors.lastname: Conrad
authors.affiliation: The Howard Hughes Medical Institute, Department of Molecular Genetics and Microbiology, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712.
authors.forename: Nodar
authors.initials: N
authors.lastname: Makharashvili
authors.affiliation: Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030.
authors.forename: Jiadong
authors.initials: J
authors.lastname: Wang
authors.affiliation: Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030.
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
authors.affiliation: Centre National de la Recherche Scientifique Unité Mixte de Recherche 8200, Institut de Cancérologie Gustave-Roussy, Université Paris-Sud, F-94805 Villejuif, France.
authors.forename: Bernard S
authors.initials: BS
authors.lastname: Lopez
authors.affiliation: The Howard Hughes Medical Institute, Department of Molecular Genetics and Microbiology, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712.
authors.forename: Tanya T
authors.initials: TT
authors.lastname: Paull
authors.affiliation: Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030.
authors.forename: Junjie
authors.initials: J
authors.lastname: Chen
authors.affiliation: Genome Damage and Stability Centre, University of Sussex, Brighton BN1 9RQ, England, UK.
authors.forename: Penny A
authors.initials: PA
authors.lastname: Jeggo
authors.affiliation: Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany lobrich@bio.tu-darmstadt.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Löbrich
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded; D059766:DNA End-Joining Repair; D004706:Endodeoxyribonucleases; D059585:G1 Phase Cell Cycle Checkpoints; D057809:HEK293 Cells; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D025941:Protein Interaction Mapping; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D051716:Replication Protein A / Q000378:metabolism; D014178:Translocation, Genetic; D025521:Tumor Suppressor Proteins; D000097868:Polo-like Kinases
chemical_list: D002352:Carrier Proteins; D004706:Endodeoxyribonucleases; D006657:Histones; D009687:Nuclear Proteins; D017346:Protein Serine-Threonine Kinases; D051716:Replication Protein A; D025521:Tumor Suppressor Proteins; C468783:H2AX protein, human; C486256:PLK3 protein, human; D000097868:Polo-like Kinases; C516794:RPA2 protein, human; C410741:RBBP8 protein, human