Figure 1

Human p53 protein activates transcription from a reporter construct in Saccharomyces cerevisiae. (A) Schematic representation of our yeast reporter construct integrated into our yeast strain. The black circle represents a single p53 responsive element from the human p21 promoter. (B) β-galactosidase assay to measure activation of the lacZ reporter gene. Wild type p53 and the indicated point mutant variants were transformed into the p53 responsive reporter strain and β-galactosidase activity in solution was determined. The activity of wild type p53 was arbitrarily set to 100%. p53R282W and p53V173A showed about 40% of activation compared to wild type p53. No activation of the reporter gene was detected in yeast cells containing the other point mutant variants. Average and standard deviation were determined from three independent experiments. (C) Growth on selective plates containing 20 mM 3-AT depends on expression of the HIS3 reporter gene and correlates with the activation of the lacZ reporter gene. Control plates consist of standard drop-out plates lacking the corresponding growth marker without 3-AT. Growth under selective conditions was dependent on activation of the p53 dependent reporter gene.