[RAD51 regulates REV1 recruitment to DNA double-strand break sites]

REV1 is one of the major Y-family DNA polymerases. It not only functions as a scaffold protein to mediate other specialized DNA polymerases to sites of lesions, but also inserts deoxycytidine across the lesion strand during translesion DNA synthesis (TLS). Meanwhile, REV1 has been reported to be involved in homologous recombination (HR) repair. Here we further explore the roles of REV1-interacting proteins RAD51 and RAD51C in REV1-mediated DNA double-strand break (DSB) repair. We found that RAD51 but not RAD51C regulates REV1 recruitment to DSB sites via pulsed laser microirradiation. Interestingly, immunofluorescence staining exhibits that REV1 also regulates RAD51 focus formation in response to CPT treatment. These results suggest that REV1 and RAD51 might be mutually dependent on each other in the REV1-related HR pathway.