title: APC/C(Cdh1) controls CtIP stability during the cell cycle and in response to DNA damage.
abstract: Human cells have evolved elaborate mechanisms for responding to DNA damage to maintain genome stability and prevent carcinogenesis. For instance, the cell cycle can be arrested at different stages to allow time for DNA repair. The APC/C(C) (dh1) ubiquitin ligase mainly regulates mitotic exit but is also implicated in the DNA damage-induced G2 arrest. However, it is currently unknown whether APC/C(C) (dh1) also contributes to DNA repair. Here, we show that Cdh1 depletion causes increased levels of genomic instability and enhanced sensitivity to DNA-damaging agents. Using an integrated proteomics and bioinformatics approach, we identify CtIP, a DNA-end resection factor, as a novel APC/C(C) (dh1) target. CtIP interacts with Cdh1 through a conserved KEN box, mutation of which impedes ubiquitylation and downregulation of CtIP both during G1 and after DNA damage in G2. Finally, we find that abrogating the CtIP-Cdh1 interaction results in delayed CtIP clearance from DNA damage foci, increased DNA-end resection, and reduced homologous recombination efficiency. Combined, our results highlight the impact of APC/C(C) (dh1) on the maintenance of genome integrity and show that this is, at least partially, achieved by controlling CtIP stability in a cell cycle- and DNA damage-dependent manner.
authors.affiliation: Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Lafranchi
authors.affiliation: Department of Medical Oncology, University Medical Center Groningen University of Groningen, Groningen, The Netherlands.
authors.forename: Harmen R
authors.initials: HR
authors.lastname: de Boer
authors.affiliation: Department of Medical Oncology, University Medical Center Groningen University of Groningen, Groningen, The Netherlands.
authors.forename: Elisabeth G E
authors.initials: EG
authors.lastname: de Vries
authors.affiliation: Department of Pharmacology, University of Washington, Seattle, WA, USA.
authors.forename: Shao-En
authors.initials: SE
authors.lastname: Ong
authors.affiliation: Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland sartori@imcr.uzh.ch m.vugt@umcg.nl.
authors.forename: Alessandro A
authors.initials: AA
authors.lastname: Sartori
authors.affiliation: Department of Medical Oncology, University Medical Center Groningen University of Groningen, Groningen, The Netherlands sartori@imcr.uzh.ch m.vugt@umcg.nl.
authors.forename: Marcel A T M
authors.initials: MA
authors.lastname: van Vugt
mesh_terms: D002352:Carrier Proteins / Q000378:metabolism*; D064200:Cdh1 Proteins / Q000378:metabolism*; D019295:Computational Biology; D004249:DNA Damage / Q000502:physiology*; D004706:Endodeoxyribonucleases; D005434:Flow Cytometry; D059565:G2 Phase Cell Cycle Checkpoints / Q000502:physiology*; D042822:Genomic Instability / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D013058:Mass Spectrometry; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009687:Nuclear Proteins / Q000378:metabolism*; D040901:Proteomics; D034622:RNA Interference
chemical_list: D002352:Carrier Proteins; D064200:Cdh1 Proteins; D009687:Nuclear Proteins; D049452:Green Fluorescent Proteins; D004706:Endodeoxyribonucleases; C410741:RBBP8 protein, human
keywords: Cdh1; CtIP; DNA damage; DNA double‐strand break repair; cell cycle