Effect of E1A-13S or E1A-d30-76 proteins on the activity of mutated versions of the K18 promoter. SW613-3 (T) or SW613-B3 (NT) cells were transfected with each of the reporter plasmids carrying the indicated mutated form of the K18(80) promoter, alone or in the presence of plasmid pE1A-13S (A and C) or plasmid pE1A-d30-76 (B and D). Luciferase activities are expressed relative to that obtained with the promoter construct alone in each cell line. Since the activities of all promoter constructs alone were adjusted to 100, they are all represented by a single pair of columns in each panel. The activity of these constructs relative to that of the wild type K18(80) promoter has been reported previously . The structure of the various mutant forms of the K18(80) promoter is schematized in E. Error bars represent the standard deviation of the mean of duplicate experimental points.