Figure 2. Repression of SALL2 promoter activity by wild type p53.

Transient co-transfections of the SALL2 P2 promoter-luciferase reporter constructs with or without p53 into different cell lines were performed as described under “Materials and Methods”. Luciferase activity was measured from cell lysates and normalized to β-galactosidase activity, and promoter activity was expressed as relative luciferase units (R.L.U). pGL3 vector served as control. A. Schematic diagram of the 2.3kb, 1.2kb and 344bp fragments of the SALL2 P2 promoter-luciferase reporter constructs with triangles representing the location of p53 half sites B. Activity of the 344bp, 1.2kb or 2.3kb promoter constructs in the absence or presence of wild type p53 in 293T cells C. Promoter activity of the 344bp promoter construct in the absence or presence of p53 in p53 (-/-) Mouse embryo fibroblasts (MEFs p53 (-/-)). D. Promoter activity of the 344 bp promoter construct in the presence of different amounts of p53 in H1299 (p53-/-) cells. E. Promoter activity of the 344 bp promoter construct in the presence of wild type p53, R175H, R249S, or R248W p53 mutants in H1299 (p53-/-) cells. The results represent three independent experiments, each assayed in triplicate. Each bar represents the mean +/- standard error. Statistical significance was determined by student t-test (** p = 0.001). Western blot for p53 overexpression are shown at the top right corner of each graph, molecular weight markers are indicated on the left of the blot.