The human angiotensin II type 1 (AT1) receptor gene was isolated and its promoter function analyzed by deletion mutant promoter/luciferase constructs in transfected Cos 7 cells. We found that epidermal growth factor enhanced the human AT1 promoter activity twofold to threefold. The region between -227 and -366 bp from the 5' end of the cDNA was mapped for a base sequence responsive to the epidermal growth factor stimulation. By computer analysis, PEA3 transcription factor was located in this region and was shown to bind to the promoter by gel shift assay in Cos 7 and HepG2 cells. These results indicated that the human AT1 receptor enhanced by epidermal growth factor may be due to PEA3 binding to the human AT1 promoter.