An ATR- and Cdc7-dependent DNA damage checkpoint that inhibits initiation of DNA replication

Mol Cell. 2003 Jan;11(1):203-13. doi: 10.1016/s1097-2765(02)00799-2.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Aphidicolin / pharmacology
  • Ataxia Telangiectasia Mutated Proteins
  • Caffeine / pharmacology
  • Cell Cycle Proteins / metabolism*
  • Chromatin / metabolism
  • DNA / drug effects
  • DNA / genetics
  • DNA / metabolism
  • DNA Damage
  • DNA Replication*
  • Enzyme Inhibitors / pharmacology
  • Etoposide / pharmacology
  • Exonucleases / metabolism
  • Humans
  • Macromolecular Substances
  • Male
  • Nucleic Acid Synthesis Inhibitors / pharmacology
  • Oocytes / physiology
  • Phosphoproteins / metabolism
  • Protein-Serine-Threonine Kinases / metabolism*
  • Signal Transduction / physiology
  • Spermatozoa / cytology
  • Spermatozoa / physiology
  • Xenopus Proteins*
  • Xenopus laevis / physiology

Substances

  • Cell Cycle Proteins
  • Chromatin
  • Enzyme Inhibitors
  • Macromolecular Substances
  • Nucleic Acid Synthesis Inhibitors
  • Phosphoproteins
  • Xenopus Proteins
  • Aphidicolin
  • Caffeine
  • Etoposide
  • DNA
  • Atr protein, Xenopus
  • CDC7 protein, Xenopus
  • CDC7 protein, human
  • ATR protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • Protein-Serine-Threonine Kinases
  • Exonucleases