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 role in DNA repair through its association with mRad51, a mammalian homologue of bacterial and yeast proteins involved in homologous recombination. A model is proposed that the critical requirement for BRACA2 in cell division and the maintenance of chromosome stability stems from its participation in recombinational processes essential for DNA replication.