FIG. 6.

(a) Diagrammatic representation of the deletion series of the ORF 73 promoter. A series of 5′ mutants were constructed by PCR amplification and ligated into pCAT-Basic. (b) Cos-7 cells were cotransfected with 2 μg of p73Δ1–6 in the presence of a transfection control plasmid, pCMVβ. Cells were harvested at 48 h posttransfection, and the cell extracts were assayed for CAT activity. Percentages of acetylation were calculated by scintillation counting of the appropriate regions of the chromatography plate and are shown in graphical format: the variations among three replicate assays are indicated. (c) Potential transcription factor binding sites within the ORF 73 promoter. The putative transcription start site and transcription factor binding sites are highlighted.