Wip1 was first identified as a gene upregulated after DNA damage in a p53-dependent manner (3). In particular, Rossi et al. analyzed the promoter region of Wip1 and confirmed Wip1 as a p53 transcriptional target (Figure 1 & Figure 2) (19). The authors identified two potential p53 response elements (p53RE) in the PPM1D promoter region, but showed that only the p53RE located in the 5′ untranslated region (5′UTR) conferred p53-responsiveness. By using reporter constructs, PCR, and chromatin immunoprecipitation (ChIP) analysis, they showed that p53 bound to the PPM1D promoter region after IR, and that the 5′UTR p53RE was responsible for the DNA damage-induced upregulation of Wip1 by p53 (19).
