Abstract
The pharmacological and functional properties of many biogenic-amine receptors have been thoroughly investigated. In contrast, knowledge about the transcriptional regulation of receptor genes is limited. Here we describe the structural and functional properties of the promoter region of a dopamine receptor-gene (Dmdop1) from Drosophila. The transcriptional start site was identified by 5'-RACE (5'-rapid amplification of cDNA ends) cloning and primer-extension analysis. A consensus site for transcriptional initiation (INR element) is located 494 bp upstream of the ATG codon of the open reading-frame. The promoter neither contains TATA- nor CAAT boxes but several GC-rich elements. Relative promoter activity was monitored by CAT reporter-gene analysis in different neuronal cell lines. The Dmdop1 promoter contains one activating (-454/+125) and two silencing regions (-1481/-454 and +125/+495). Interestingly, one silencing region harbours a CRE (cAMP responsive element) site. Since the DmDOP1 receptor leads to cAMP production in cells, the CRE site might contribute to the receptors' own expression by cAMP-dependent transcription factors.
