Promoter analysis of mouse estrogen-responsive finger protein (efp) gene: mouse efp promoter contains an E-box that is also conserved in human.

The estrogen-responsive finger protein (efp) containing a RING finger motif has been identified as an estrogen-responsive gene in human and mouse. Here, we have characterized the basal promoter region of the mouse efp gene. The promoter lacks the TATA motif, and transcription initiation sites are found at positions -38T, -64A and -73C from the translation initiation site. Deletion analysis of the 5'-flanking region using Jyg-Mc(B) mouse breast cancer cells indicates that the sequence encompassing from -139 to -1 has a basal transcription activity. This region is GC-rich in both mouse and human promoters, and the E-box is precisely matched on the sequence alignment. A mutation experiment with E-box shows that the E-box is functionally active. An electrophoretic mobility shift assay using Jyg-Mc(B) nuclear extracts shows that a transcription factor, USF-1 binds to the E-box in the mouse efp promoter. It has been shown that the E-box in the human efp promoter is indispensable for basal transcriptional activity and binds USF-1. These findings suggest that the mouse efp promoter is regulated by a similar mechanism to that of the human. In mouse, however, we have not found a negative regulatory region that is present in human promoter.