Orphan receptor Arp-1 binds to the nucleotide sequence located between TATA box and transcriptional initiation site of the human angiotensinogen gene and reduces estrogen induced promoter activity.

摘要

Human angiotensinogen gene contains a C/A polymorphism at 20 bases upstream from the transcriptional initiation site. This sequence binds to the estrogen receptor when nucleoside A is present at this site and reporter constructs containing human angiotensinogen gene promoter with nucleoside A at -20 are transactivated on co-transfection of estrogen receptor in HepG2 cells followed by estrogen treatment. We show here that orphan receptor, Arp-1, which belongs to the COUP family of transcription factors also binds to this sequence. Co-transfection of Arp-1 reduces estrogen induced promoter activity of reporter constructs containing human angiotensinogen gene promoter. On the other hand co-transfection of Arp-1 does not have a significant effect on estrogen induced promoter activity of reporter constructs containing rat angiotensinogen gene promoter. Our data suggests that human and rat angiotensinogen genes are regulated in a different manner by estrogens.