Role of RAD51C and XRCC3 in genetic recombination and DNA repair

J Biol Chem. 2007 Jan 19;282(3):1973-9. doi: 10.1074/jbc.M609066200. Epub 2006 Nov 17.

Abstract

In germ line cells, recombination is required for gene reassortment and proper chromosome segregation at meiosis, whereas in somatic cells it provides an important mechanism for the repair of DNA double-strand breaks. Five proteins (RAD51B, RAD51C, RAD51D, XRCC2, and XRCC3) that share homology with RAD51 recombinase and are known as the RAD51 paralogs are important for recombinational repair, as paralog-defective cell lines exhibit spontaneous chromosomal aberrations, defective DNA repair, and reduced gene targeting. The paralogs form two distinct protein complexes, RAD51B-RAD51C-RAD51D-XRCC2 and RAD51C-XRCC3, but their precise cellular roles remain unknown. Here, we show that, like MLH1, RAD51C localized to mouse meiotic chromosomes at pachytene/diplotene. Using immunoprecipitation and gel filtration analyses, we found that Holliday junction resolvase activity associated tightly and co-eluted with the 80-kDa RAD51C-XRCC3 complex. Taken together, these data indicate that the RAD51C-XRCC3-associated Holliday junction resolvase complex associates with crossovers and may play an essential role in the resolution of recombination intermediates prior to chromosome segregation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Movement
  • Chromatin Immunoprecipitation
  • Chromatography, Gel
  • Chromosome Aberrations
  • DNA Breaks, Double-Stranded
  • DNA Repair
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • DNA-Binding Proteins / physiology*
  • HeLa Cells
  • Humans
  • Male
  • Mice
  • Protein Binding
  • Recombination, Genetic*

Substances

  • DNA-Binding Proteins
  • RAD51C protein, human
  • X-ray repair cross complementing protein 3