Figure 5.

Mutant p53 up-regulates the Axl promoter in H1299 cells independent of the p63 site. Two deletion mutants of the Axl promoter were constructed and tested for promoter activity in H1299 cells in the presence and absence of mutant p53 and p63 to determine if the putative p63 binding site is required for mutant p53–mediated transactivation. The conditions of the assay were similar to those described in the caption of Figure 4. The data indicate that mutant p53 does not require the p63 binding site to transactivate the Axl promoter. H1299 cells were also co-transfected with pGL3 basic or the larger Axl deletion mutant and an empty vector or mutant p53 to ensure the transactivation capability was not lost. Data are shown as fold activation over the control. Experiments were performed in triplicate. Error bars showing standard deviations are indicated.