title: SCFbetaTrCP-mediated degradation of Claspin regulates recovery from the DNA replication checkpoint response.
abstract: During replicative stress, Claspin mediates the phosphorylation and consequent activation of Chk1 by ATR. We found that during recovery from the DNA replication checkpoint response, Claspin is degraded in a betaTrCP-dependent manner. In vivo, Claspin is phosphorylated in a canonical DSGxxS degron sequence, which is typical of betaTrCP substrates. Phosphorylation of Claspin is mediated by Plk1 and is essential for binding to betaTrCP. In vitro ubiquitylation of Claspin requires betaTrCP, Plk1, and an intact DSGxxS degron. Significantly, expression of a stable Claspin mutant unable to bind betaTrCP prolongs the activation of Chk1, thereby attenuating the recovery from the DNA replication stress response and significantly delaying entry into mitosis. Thus, the SCFbetaTrCP-dependent degradation of Claspin is necessary for the efficient and timely termination of the DNA replication checkpoint. Importantly, in response to DNA damage in G2, Claspin proteolysis is inhibited to allow the prompt reestablishment of the checkpoint.
authors.affiliation: Department of Pathology, NYU Cancer Institute, New York University School of Medicine, MSB 599, New York, New York 10016, USA.
authors.forename: Angelo
authors.initials: A
authors.lastname: Peschiaroli
authors.forename: N Valerio
authors.initials: NV
authors.lastname: Dorrello
authors.forename: Daniele
authors.initials: D
authors.lastname: Guardavaccaro
authors.forename: Monica
authors.initials: M
authors.lastname: Venere
authors.forename: Thanos
authors.initials: T
authors.lastname: Halazonetis
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Sherman
authors.forename: Michele
authors.initials: M
authors.lastname: Pagano
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000502:physiology*; D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D045744:Cell Line, Tumor; D004249:DNA Damage / Q000502:physiology; D004261:DNA Replication / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D006657:Histones / Q000378:metabolism; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding; D034741:RNA, Small Interfering / Q000235:genetics; D044843:SKP Cullin F-Box Protein Ligases / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D025801:Ubiquitin / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C488158:CLSPN protein, human; D018797:Cell Cycle Proteins; D006657:Histones; D034741:RNA, Small Interfering; D025801:Ubiquitin; D044843:SKP Cullin F-Box Protein Ligases; D006918:Hydroxyurea