Figure 4.

Transcriptional activation elicited by DNA-tethered TBP is affected by the reporter template used. All the Gal4 derivatives were expressed from the SV40 enhancer-promoter. DNA (0.5 μg) encoding the nonclassical Gal4 derivatives and Gal4 + Sp1, or 0.25 μg of DNA encoding Gal4 + VP16, was cotransfected with 0.5 μg of either template A (white bars) or template B (black bars) and, as an internal control, 0.2 μg of a plasmid encoding lacZ expressed from the CMV enhancer-promoter. The lipofectamine method was used for transfecting HeLa cells with the indicated plasmids, and results of luciferase assays are shown.