HUMAN MINERALOCORTICOID RECEPTOR GENOMIC STRUCTURE AND IDENTIFICATIONOF EXPRESSED ISOFORMS

Most of the known effects of aldosterone are mediated by the mineraloc orticoid receptor, an intracellular receptor belonging to the steroid/ thyroid hormone/retinoic acid receptor superfamily. We determined the genomic structure of the human MR (hMR) and identified 10 exons in the gene, including two exons (1 alpha and 1 beta) that encode different 5'-untranslated sequence. Expression of the two different hMR variants is under the control of two different promoters that contain no obvio us TATA element, but multiple GC boxes. Our results indicate that hMR expression is regulated by alternative promoters perhaps in a tissue- or developmental-specific manner.