HETERODIMERIZATION BETWEEN MINERALOCORTICOID AND GLUCOCORTICOID RECEPTORS INCREASES THE FUNCTIONAL DIVERSITY OF CORTICOSTEROID ACTION

Gene regulation by steroids is mediated by the binding of the endogeno us or pharmacological ligand to the corresponding nuclear receptor. Li gand-activated steroid receptors usually regulate the expression of re sponsive genes by binding to common response elements on DNA as homodi mers. However, recent findings indicate that mineralocorticoid and glu cocorticoid receptors are able to interact by forming heterodimers. In tissues coexpressing both of these corticosteroid receptors, heterodi merization between them may be a hitherto unrecognized modality for th e transcriptional regulation of corticosteroid-responsive genes. In th is review, Thorsten Trapp and Florian Holsboer discuss the potential i mpact of this heterodimerization on corticosteriod physiology and phar macology.