title: An ATR- and Cdc7-dependent DNA damage checkpoint that inhibits initiation of DNA replication.
abstract: We have analyzed how single-strand DNA gaps affect DNA replication in Xenopus egg extracts. DNA lesions generated by etoposide, a DNA topoisomerase II inhibitor, or by exonuclease treatment activate a DNA damage checkpoint that blocks initiation of plasmid and chromosomal DNA replication. The checkpoint is abrogated by caffeine and requires ATR, but not ATM, protein kinase. The block to DNA synthesis is due to inhibition of Cdc7/Dbf4 protein kinase activity and the subsequent failure of Cdc45 to bind to chromatin. The checkpoint does not require pre-RC assembly but requires loading of the single-strand binding protein, RPA, on chromatin. This is the biochemical demonstration of a DNA damage checkpoint that targets Cdc7/Dbf4 protein kinase.
authors.affiliation: Department of Genetics and Development, Columbia University, New York, NY 10032, USA.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Costanzo
authors.forename: David
authors.initials: D
authors.lastname: Shechter
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Lupardus
authors.forename: Karlene A
authors.initials: KA
authors.lastname: Cimprich
authors.forename: Max
authors.initials: M
authors.lastname: Gottesman
authors.forename: Jean
authors.initials: J
authors.lastname: Gautier
mesh_terms: D000818:Animals; D016590:Aphidicolin / Q000494:pharmacology; D064007:Ataxia Telangiectasia Mutated Proteins; D002110:Caffeine / Q000494:pharmacology; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage; D004261:DNA Replication; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005047:Etoposide / Q000494:pharmacology; D005092:Exonucleases / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances; D008297:Male; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D009865:Oocytes / Q000502:physiology; D010750:Phosphoproteins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000502:physiology
chemical_list: D018797:Cell Cycle Proteins; D002843:Chromatin; D004791:Enzyme Inhibitors; D046911:Macromolecular Substances; D019384:Nucleic Acid Synthesis Inhibitors; D010750:Phosphoproteins; D029867:Xenopus Proteins; D016590:Aphidicolin; D002110:Caffeine; D005047:Etoposide; D004247:DNA; C576898:Atr protein, Xenopus; C489405:CDC7 protein, Xenopus; C068619:CDC7 protein, human; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; D005092:Exonucleases