A critical region in the mineralocorticoid receptor for aldosterone binding and activation by cortisol: evidence for a common mechanism governing ligand binding specificity in steroid hormone receptors.

A panel of chimeras created between the MR and the glucocorticoid receptor displayed a dissociation between cortisol binding and transactivation and, intriguingly, only those that bound aldosterone with high affinity were activated by cortisol, suggesting a common mechanism that underlies specificity of ald testosterone binding and the ability of cortisol to activate the MR.