Figure 4.

CGB7 promoter activity is induced by p53. (A) Dual luciferase-reporter assays were performed in SaOS-2 cells after cotransfection of either CGB1 (B1), CGB5 (B5), CGB7 (B7) or LHB promoter-reporter constructs together with plasmids expressing wild-type or mutant p53 and a Renilla luciferase transfection control plasmid. Firefly luciferase was measured and normalized to Renilla luciferase activity. Fold induction by p53 is displayed as the ratio of promoter activities obtained with wild-type compared with DNA-binding mutant p53 protein. The empty reporter vector served as control (mean ± SD, n ≥ 3, **p < 0.01). (B) The p53 binding site in the CGB7 promoter is not conserved in the other CGB genes. Alignment of CGB and LHB promoter regions around the p53 binding site (framed) of the CGB7 promoter. Positions relative to the transcriptional start sites are given. Identical nucleotides are presented by dots. Spaces are indicated by lines.