A requirement for PARP-1 for the assembly or stability of XRCC1 nuclear foci at sites of oxidative DNA damage

Nucleic Acids Res. 2003 Oct 1;31(19):5526-33. doi: 10.1093/nar/gkg761.


The molecular role of poly (ADP-ribose) polymerase-1 in DNA repair is unclear. Here, we show that the single-strand break repair protein XRCC1 is rapidly assembled into discrete nuclear foci after oxidative DNA damage at sites of poly (ADP-ribose) synthesis. Poly (ADP-ribose) synthesis peaks during a 10 min treatment with H2O2 and the appearance of XRCC1 foci peaks shortly afterwards. Both sites of poly (ADP-ribose) and XRCC1 foci decrease to background levels during subsequent incubation in drug-free medium, consistent with the rapidity of the single-strand break repair process. The formation of XRCC1 foci at sites of poly (ADP-ribose) was greatly reduced by mutation of the XRCC1 BRCT I domain that physically interacts with PARP-1. Moreover, we failed to detect XRCC1 foci in Adprt1-/- MEFs after treatment with H2O2. These data demonstrate that PARP-1 is required for the assembly or stability of XRCC1 nuclear foci after oxidative DNA damage and suggest that the formation of these foci is mediated via interaction with poly (ADP-ribose). These results support a model in which the rapid activation of PARP-1 at sites of DNA strand breakage facilitates DNA repair by recruiting the molecular scaffold protein, XRCC1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CHO Cells
  • Cell Nucleus / chemistry
  • Cell Nucleus / metabolism
  • Cell Survival
  • Cells, Cultured
  • Cricetinae
  • DNA Damage*
  • DNA Repair*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Hydrogen Peroxide / pharmacology
  • Mice
  • Mutation
  • Oxidants / pharmacology
  • Oxidative Stress
  • Poly Adenosine Diphosphate Ribose / biosynthesis
  • Poly(ADP-ribose) Polymerases / genetics
  • Poly(ADP-ribose) Polymerases / physiology*
  • Protein Structure, Tertiary
  • X-ray Repair Cross Complementing Protein 1


  • DNA-Binding Proteins
  • Oxidants
  • X-ray Repair Cross Complementing Protein 1
  • Xrcc1 protein, mouse
  • Poly Adenosine Diphosphate Ribose
  • Hydrogen Peroxide
  • Poly(ADP-ribose) Polymerases