FIG. 3.

Transcriptional activation by p53 phosphorylation mutant proteins assessed by using a luciferase reporter assay. p53 phosphorylation mutant proteins (50 ng) were cotransfected into Saos-2 cells with 5 μg of either a human p21^Waf1/Cip1, Mdm2, or bax luciferase reporter construct. Five micrograms of pCB6+βgal was included to assess transfection efficiency. Cells were harvested at 24 h, lysed, and assessed for luciferase and β-galactosidase activities. Each graph shows fold activation relative to that of the pCB6+ control harvested at 24 h.