BRCA2 is required for homology-directed repair of chromosomal breaks

Mol Cell. 2001 Feb;7(2):263-72. doi: 10.1016/s1097-2765(01)00174-5.


The BRCA2 tumor suppressor has been implicated in the maintenance of chromosomal stability through a function in DNA repair. In this report, we examine human and mouse cell lines containing different BRCA2 mutations for their ability to repair chromosomal breaks by homologous recombination. Using the I-SceI endonuclease to introduce a double-strand break at a specific chromosomal locus, we find that BRCA2 mutant cell lines are recombination deficient, such that homology-directed repair is reduced 6- to >100-fold, depending on the cell line. Thus, BRCA2 is essential for efficient homology-directed repair, presumably in conjunction with the Rad51 recombinase. We propose that impaired homology-directed repair caused by BRCA2 deficiency leads to chromosomal instability and, possibly, tumorigenesis, through lack of repair or misrepair of DNA damage.

Publication types

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

MeSH terms

  • Animals
  • BRCA2 Protein
  • Blotting, Southern
  • Chromosome Breakage / genetics*
  • DNA Damage / genetics
  • DNA Repair / genetics*
  • DNA-Binding Proteins / metabolism
  • Exons / genetics
  • Gene Targeting
  • Genes, Reporter
  • Humans
  • Mice
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Precipitin Tests
  • Protein Binding
  • Rad51 Recombinase
  • Recombination, Genetic*
  • Sequence Deletion / genetics
  • Sequence Homology, Nucleic Acid*
  • Stem Cells
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transfection
  • Tumor Cells, Cultured


  • BRCA2 Protein
  • DNA-Binding Proteins
  • Neoplasm Proteins
  • Transcription Factors
  • RAD51 protein, human
  • Rad51 Recombinase
  • Rad51 protein, mouse