BRCA1 associates with human papillomavirus type 18 E2 and stimulates E2-dependent transcription

BRCA1 is a breast and ovarian cancer-related tumor suppressor and has a role in transcriptional activation. We show here that BRCA1 enhances human papillomavirus type 18 (HPV-18) E2-dependent transcription in vivo. Using biochemical approaches, we discovered that BRCA1 interacts with the carboxyl-terminus of HPV-18 E2 protein in vivo and in vitro. Point mutations in the C-terminus make BRCA1 defective in transcriptional activation in E2-dependent transcription. This finding suggests that the C-terminus of BRCA1 is important for E2-dependent transcription. A chromatin immunoprecipitation assay indicated that BRCA1 is recruited onto the E2-dependent promoter region though E2 tethered to E2 binding sites in vivo. These results implicate that BRCA1 plays a role in E2-dependent transcription.