Cloning and characterization of the functional promoter of mouse estrogen receptor β gene

Abstract

The recently discovered estrogen receptor β (ERβ) exhibits some properties distinct from those of the classical estrogen receptor, ERα. To elucidate the mechanism underlying the regulation of ERβ gene expression, we cloned and characterized the 5′-flanking (promoter) region of the mouse ERβ (mERβ) gene. A TATA-like motif was found in the 5′-flanking region, and transcription initiation sites were mapped 24 bp and 27 bp downstream from the motif by primer extension analysis and 5′-rapid amplification of cDNA ends. The mERβ promoter contains several putative cis-acting elements, many of which are also found in the mouse ERα promoter. Therefore, the expression of both ERs may be partially regulated by a common mechanism. Luciferase assays revealed that the mERβ promoter activity paralleled the endogenous expression levels of mERβ in several cell lines. Successive 5′-deletion analyses showed that element(s) critical for its basal activity and negative regulatory element(s) are located in the sequences −90/+33 and −505/−372, respectively. The characterization of the mERβ promoter will allow further studies to investigate the transcriptional regulation of mERβ.