Molecular cloning and functional analysis of the rat mu opioid receptor gene promoter.

The rat mu opioid receptor gene promoter was cloned and characterized. It has a few features in common with the mouse gene, e.g. the lack of a classical TATA box and the fact that several transcriptional start sites are used. The overall homology between the two species is greater than 85%. Functional analysis of the promoter was performed using transient expression of rat mu opioid receptor-reporter gene constructs in the mu opioid receptor expressing cell line SH SY5Y and in non mu opioid receptor expressing cell lines. A promoter region was defined which confers both high basal and TPA and forskolin stimulated reporter gene expression in SH SY5Y cells.