p53 regulates the expression of human angiotensin II AT(2) receptor interacting protein (ATIP1) gene.

Angiotensin II AT(2) receptor interacting protein 1 (ATIP1) has been recently identified as a tumor suppressor. In the present study, a 2.2 kb fragment of the 5' flanking region of the human ATIP1 gene was cloned, and its promoter activity was confirmed. Two putative p53 binding sites were identified in the minimal promoter. Cisplatin treatment and ectopic expression of p53 led to enhanced ATIP1 expression. Knockdown of p53 reduced the ATIP1 expression. The direct interaction of p53 and the ATIP1 promoter was confirmed by reporter gene and chromatin-immunoprecipitation assays. When the p53 sites were mutated, the effect of p53 on ATIP1 promoter was eliminated. The results suggest that the ATIP1 gene is regulated by p53 at the transcriptional level, and that it may play an important role in cancer initiation and progression.