FIG. 9.
Kinetics of p53 binding to downstream promoters in the HIp53 cell line. Exogenous p53 was induced with the addition of PonA for the indicated times. The DNA derived from p53-specific immunocomplexes was PCR amplified using primers for the p21Waf1 (A), MDM2 (B), or PIG3 (C) promoter. PCRs were resolved by PAGE, the gels were stained with ethidium bromide, and the PCR products were quantified by densitometry. Data are expressed as fold of the 2-h (X-Link) PCR signal. The level of PCR products derived from control cells was negligible. The results are representative of at least three independent experiments.