Ligand binding domain of the mineralocorticoid receptor, a member of the nuclear receptor superfamily
The ligand binding domain of the mineralocorticoid receptor (MR): MR, also called aldosterone receptor, is a member of nuclear receptor superfamily involved in the regulation of electrolyte and fluid balance. The receptor is activated by mineralocorticoids such as aldosterone and deoxycorticosterone as well as glucocorticoids, like cortisol and cortisone. Binding of its ligand results in its translocation to the cell nucleus, homodimerization and binding to hormone response elements (HREs) present in the promoter of MR controlled genes. This results in the recruitment of the coactivators and the transcription of the activated genes. MR is expressed in many tissues and its activation results in the expression of proteins regulating electrolyte and fluid balance. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, MR has a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD ). The LBD, in addition to binding ligand, contains a ligand-dependent activation function-2 (AF-2).