FIG. 2.

BPV-1 E2 binds to transcriptionally active promoters. Chromatin samples from control (fh-only) and BPV-1 E2-expressing C33A cells were subjected to ChIP by IgG (A) and specific antibodies against BPV-1 E2 (B201) (B), Brd4 (C), RNA pol II (8WG16) (D), and H3K4me3 (E). ChIP DNA samples were analyzed by real-time PCR with specific primer sets for the target promoters indicated. The first promoter (HOXB1) was identified as negative for BPV-1 E2 binding by CHIP-chip analysis, and all of the others were positive for E2 binding. ChIP signals were expressed as percentages of chromatin DNA immunoprecipitated from the input amount of chromatin. TUBB, beta tubulin.