STUDY OF HUMAN μ‐OPIOID RECEPTOR GENE

Analgesia and addiction can be mediated through opioid receptor in human, and the μ‐opioid receptor is the key player. Expression of a gene requires transcription via its promoter. Although mouse μ opioid receptor promoter has been studied, little is known about human promoter. Recently, we began to investigate the promoter of human μ opioid receptor gene. A single transcriptional start site was reported previously. Using PCR, two plasmids, p422 and p357, containing different lengths of gene were constructed using the luciferase reporter vector. These plasmids were tested. Both p422 and p357 plasmids displayed significant activities, suggesting the p357 with a shorter genomic fragment containing the active promoter. This region also possessed a CT‐rich region with 83% homology to that of mouse species. Results further showed that the CT containing plasmid displayed a significant activity, while the reversed orientation displayed no activity, suggesting this region possessed the orientation‐dependent promoter activity. However, contribution of this CT region to the activity was about 20% of total activity. Therefore, we examined regions involving the promoter activity using deletional analyses in this study. Preliminary results suggested multiple regions involved in the promoter of human μ opioid receptor gene, implicating any genetic mutation within these regions may influence its gene expression.