Fig. 6. Comparison of p53-induced transcriptional transactivation activity in revertants and in HeLa cells using reporter constructs harboring multiple p53 wild-type (pG13CAT) or mutant (-MG15CAT) consensus binding sequences. Promoter activities were assessed by measuring the rate of CAT conversion in lysates prepared from 5 x 106 cells transiently transfected with 10 µg of pG13CAT or pMG15CAT. No DNA, background CAT conversion rates determined in lysates from cells that were electropulsed in the absence of DNA. CAT values are normalized by transfection efficiency as described by Bahramian and Zarbl (33) . {square}, no DNA; , pMG15CAT; , pG13CAT.