p531-65 can compete with wild-type p53 for binding to GATA-1 and reduce the inhibition of p53. (A) A schematic of constructs made by inserting translation termination signals in the CMV p53 expression vector to generate peptides 1-65 and 1-40 is shown. (B) A transfection assay in which CMV Renilla luciferase, p53 Luc reporter plasmid, and CMV p53 were present in all samples and expression plasmids for mGATA-1 were added to samples 2-6 along with 6 μg of empty vector (bar 2), 5 or 6 μg of CMV p53 1-65 (bars 3 and 4), or CMVp53 1-40 (bars 5 and 6), as indicated. For the last 2 samples, GATA-1CM, a mutant that does not interfere with transactivation by p53, was used instead of wild-type GATA-1, and 6 μg of CMV 1-65 (bar 7) or 6 μg of CMV 1-40 (bar 8) was added. Normalization is as described in the Figure 6 legend with the average of 5 μg of GATA-1 CM 65 and 40 samples set to 100%. Results are the average of 3 experiments, and error bars indicate the standard deviation. Means of equal weights of DNA were compared by Student t test, as indicated; *P < .05 and ** P < .005.
