FIG. 7.

PPBP-polh promoter interaction is required for transcription in vivo. (A) Luciferase activity of the reporter construct pKNluc (pKN) is decreased in the presence of increasing amounts of the competitor plasmid pAJpol (C). The total amount of transfected plasmid DNA was normalized to 20 μg with pUC18. The bars are labeled as follows: pKN, 10 μg of pKNluc in the absence of both competitor and pUC18; pKN+CO, 10 μg of pKNluc cotransfected with 10 μg of pUC18 in the absence of competitor; pKN+C2.5, 10 μg of pKNluc cotransfected with 2.5 μg of competitor; pKN+C5, 10 μg of pKNluc cotransfected with 5 μg of competitor; pKN+C10, 10 μg of pKNluc cotransfected with 10 μg of competitor. Southern hybridization of a DNA dot blot of transfected cells is shown in the right-hand panel. Replicates of three dilutions of cells from each transfection set were blotted and probed with the radiolabeled luc gene. Uninfected cells and vAcluc (a recombinant virus carrying the luc gene in place of the polyhedrin gene)-infected cells are shown as negative and positive controls, respectively. (B) Luciferase activity of the reporter construct pKNluc (pKN) is decreased in the presence of increasing amounts of the competitor plasmid pAJpol (C) and in the presence of 1 μg of α-amanitin/ml added 8 h posttransfection. The bars are labeled as in panel A. The right-hand panel shows a dot blot of cells from each transfection set with the radiolabeled luc fragment as a probe. Error bars indicate standard deviations.