Mechanism of RAD51-dependent DNA interstrand cross-link repair

Science. 2011 Jul 1;333(6038):84-7. doi: 10.1126/science.1204258.

Abstract

DNA interstrand cross-links (ICLs) are toxic DNA lesions whose repair in S phase of eukaryotic cells is incompletely understood. In Xenopus egg extracts, ICL repair is initiated when two replication forks converge on the lesion. Dual incisions then create a DNA double-strand break (DSB) in one sister chromatid, whereas lesion bypass restores the other sister. We report that the broken sister chromatid is repaired via RAD51-dependent strand invasion into the regenerated sister. Recombination acts downstream of FANCI-FANCD2, yet RAD51 binds ICL-stalled replication forks independently of FANCI-FANCD2 and before DSB formation. Our results elucidate the functional link between the Fanconi anemia pathway and the recombination machinery during ICL repair. In addition, they demonstrate the complete repair of a DSB via homologous recombination in vitro.

Publication types

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

MeSH terms

  • Animals
  • Chromatids / metabolism
  • DNA / metabolism*
  • DNA Breaks, Double-Stranded*
  • DNA Repair*
  • DNA Replication
  • Fanconi Anemia Complementation Group D2 Protein / genetics
  • Fanconi Anemia Complementation Group D2 Protein / metabolism
  • Fanconi Anemia Complementation Group Proteins / metabolism
  • Protein Binding
  • Rad51 Recombinase / metabolism*
  • Recombinant Proteins / metabolism
  • Recombination, Genetic
  • Replication Protein A / metabolism
  • Xenopus Proteins / metabolism*
  • Xenopus laevis

Substances

  • FANCI Protein, Xenopus
  • Fanconi Anemia Complementation Group D2 Protein
  • Fanconi Anemia Complementation Group Proteins
  • Recombinant Proteins
  • Replication Protein A
  • Xenopus Proteins
  • DNA
  • RAD51 protein, Xenopus
  • Rad51 Recombinase