Figure 4.

Sequence-specific transcriptional-transactivation activity of p53. Promoter activities of p21/waf1 and bax were detected after cotransfection of p53-responsive reporter constructs with empty control, p33ING1b, or p33ING2 expression vectors in RKO or RKO E6 cells. The luciferase activities from the reporter constructs were measured with a luminometer. Relative luciferase activities (RLAs) were calculated by dividing the luciferase activity by the protein concentration. Results represent the means ± SD of six independent experiments. Differences in the relative luciferase activities were analyzed by using the Student's t test.