FIG. 1.

Ectopic expression of the Brd4 CTD inhibits transient replication of the full-length BPV1 genome in C127 cells. Approximately 3 μg of linearized BPV1 genomic DNA excised from pML BPV1 plasmid was transfected into C127 cells by electroporation, together with either 1 or 3 μg of pCGCTD vector (lanes 4 to 7) or with pCGdXS as a control (lanes 8 to 11). Low-molecular-weight DNA was extracted at day 2 or 3 after transfection, digested with HindIII (to linearize BPV1 DNA) and DpnI (to digest bacterially methylated unreplicated DNA), and analyzed by Southern blotting using a radioactively labeled probe specific to BPV1 DNA. Lane 1, mock-transfected cells 3 days after transfection; lanes 2 and 3, cells transected with BPV1 DNA alone. The migration of linearized BPV1 genomic DNA and shorter DpnI fragments from unreplicated plasmid DNA is indicated on the right.