Mineralocorticoid receptor isoforms

Since the first cloning of members of the nuclear receptor superfamily, it has become evident that different isoforms are generated from single genes by various mechanisms such as utilization of alternative promoters, alternative splicing, and use of different translation initiation or polyadenylation sites. Different mineralocorticoid receptor mRNA isoforms have been identified in human and rat, which are submitted to tissue-specific expression and regulation. Recent studies indicate the existence of receptor variants with putative different functional properties, which could account for differences in target cell responsiveness to hormones. We review molecular mechanisms involved in generation of mRNA or protein isoforms and discuss the potential physiopathologic implications of mineralocorticoid receptor variants.