THE P53 TUMOR-SUPPRESSOR INHIBITS TRANSCRIPTION OF THE TATA-LESS MOUSE DP1 PROMOTER

Cell cycle progression is subject to several regulatory controls, of w hich the p53 protein plays a major role in growth arrest, subsequent t o the detection of cellular aberrations. It is well documented that p5 3 has the ability to inhibit transcription driven by several promoters , possibly via distinct mechanisms. In this report, we show that expre ssion of the cell cycle regulatory transcription factor DP1 is strongl y inhibited by p53, at the level of transcription and probably through the basal TATA-less promoter. This inhibitory activity has a relative specificity for the DP1 promoter compared with the functionally relat ed E2F1 promoter or unrelated promoters such as those of the transcrip tion factor ATFa or the thymidine kinase gene. Inhibition of DPI trans cription has implications in one of the several possible mechanisms th rough which p53 induces cell cycle arrest.