BRCA1 REQUIRED FOR TRANSCRIPTION-COUPLED REPAIR OF OXIDATIVE DNA-DAMAGE

The breast and ovarian cancer susceptibility gene BRCA1 encodes a zinc finger protein of unknown function. Association of the BRCA1 protein with the DNA repair protein Rad51 and changes in the phosphorylation a nd cellular Localization of the protein after exposure to DNA-damaging agents are consistent with a role for BRCA1 in DNA repair. Here, it i s shown that mouse embryonic stem cells deficient in BRCA1 are defecti ve in the ability to tarry out transcription-coupled repair of oxidati ve DNA damage, and are hypersensitive to ionizing radiation and hydrog en peroxide. These results suggest that BRCA1 participates, directly o r indirectly, in transcription-coupled repair of oxidative DNA damage.