FIG. 7.

pOri16L repression by the HPV16E2 protein. SCC-13 cells were transfected with 0.05 μg of pRL-TK, 1 μg of each pOri16L template, and either 0.5 μg of pCMV₄-XS or 0.5 μg of pCMV-E2₁₆. Dual luciferase assays were performed on cell extracts prepared at 36 h posttransfection. The luciferase activity for each cell lysate was expressed as the ratio between the firefly and Renilla luciferase activities. The levels of repression were calculated by dividing the basal promoter activity (transfections with the pCMV₄-XS plasmid) by the promoter activity in the presence of the E2 protein. The results from three independent experiments are plotted for each set of templates: (A) E2BS#3; (B) E2BS#2; and (C) E2BS#1. Error bars correspond to the standard deviation for each data set.