Mineralocorticoid Receptor Antibody

NR3C2 (nuclear recepttor subfamily 3, group C, member 2) also known as MR (mineralocorticoid receptor) is a protein that in humans is encoded by the NR3C2 gene that is located on chromosome 4q31.1-31.2. It belongs to the nuclearreceptor family where the ligand diffuses into cells, interacts with the MR and results in a signal transduction affecting specific gene expression in the nucleus. MR is expressed in many tissues, such as the kidney, colon, heart, central nervous system(hippocampus), brown adipose tissue and sweat glands. In epithelial tissues, its activation leads to the expression of proteins regulating ionic and water transports(mainly the epithelial sodium channel or ENaC, Na+/K+ pump, serum and glucocorticoid induced kinase or SGK1) resulting in the reabsoprtion of sodium, and as a consequence an increase in extracellular volume, increase in blood pressure, and an excretion of potassium to maintain a normal salt concentration in the body. The protein is activated by mineralocorticoids such as aldosterone and deoxycorticosterone as well as glucocorticoids, like cortisol. In intact animals, the MR is protected from glucocorticoids by co-localization of an enzyme, 11beta-hydroxysteroid dehydrogenase type 2(11beta-HSD2), that converts cortisol to inactive cortisone. It also responds to some progestins. Spironolactone and eplerenone are MR antagonists. Activation of the mineralocorticoid receptor, upon the binding of its ligand aldosterone, results in its translocation to the cell nucleus, homodimerization and binding to hormone response elements present in the promoter of some genes. This results in the complex recruitment of the transcriptional machinery and the transcription into mRNA of the DNA sequence of the activated genes.