The breast cancer susceptibility gene, BRCA2: at the crossroads between DNA replication and recombination?

The identification and cloning of the familial breast cancer susceptibility gene, BRCA2, has excited much interest in its biological functions. Here, evidence is reviewed that the protein encoded by BRCA2 has an essential rol e in DNA repair through its association with mRad51, a mammalian homologue of bacterial and yeast proteins involved in homologous recombination. A mod el is proposed that the critical requirement for BRCA2 in cell division and the maintenance of chromosome stability stems from its participation in re combinational processes essential for DNA replication.