10 exons; 363,729 bases DNA.

Multiple (at least four) mRNA isoforms are generated by alternative transcription or slicing events. Multiple mRNA isoforms are translated into various protein variants.

984 amino acids. Like all member of the nuclear receptor superfamily, the MR has 3 major domains: an N-terminal domain (NTD), a DNA-binding domain (DBD) and a ligand-binding domain (LBD). The NTD (602 amino acids) is composed of several functional domains (AF-1a, a central domain and AF-1b) that recruit various coregulators responsible for selectively modulating the transcriptional activity of MR. The DBD (66 amino acids) recognizes specific target DNA sequences or hormone response elements. The LBD (251 amino acids) is a multifunctional domain allowing selective hormone binding. The LBD includes the ligand-dependent AF-2 functional domain, which undergoes a rearrangement upon ligand binding.

Ubiquitous. MR expression has been reported in the kidney, colon, breast, salivary glands, sweat glands, liver, cardiomyocytes, endothelial cells, lung, central nervous system (hippocampus, hypothalamus), ocular tissues (retina, iris-ciliary body), adipose tissues (white and brown), inner ear, skin, placenta, uterus, ovaries and testis.

Cytoplasm, nucleus, endoplasmic reticulum membrane, peripheral membrane: cytoplasmic and nuclear in the absence of ligand; nuclear after ligand-binding. When bound to 11 beta-hydroxysteroid dehydrogenase type 2 (11 beta-HSD2), it is found associated with the endoplasmic reticulum membrane.

Transcription factor activity, receptor activity, protein binding, sequence-specific DNA binding, steroid binding, steroid hormone receptor activity, metal ion binding, zinc ion binding.

Member of the nuclear hormone receptor family, NR3 subfamily.

Loss-of-function mutations. About 50 distinct mutations in the human MR are known to be responsible for pseudohypoaldosteronism type 1 (PHA1). This is an autosomal genetic disorder caused by loss-of-function mutations. The mutations reported are missense, nonsense, frameshift, splice site mutations and deletions. PHA1 is characterized by salt wasting due to loss-of-function of the MR in the target organs. There are 2 forms of PHA1: the autosomal dominant form, which may be severe at birth, but symptoms remit with age, and the recessive form, which manifests with more severe symptoms persisting into adulthood.
Gain-of-function mutations. Only one mutation, to date, is known to result in a gain-of-function of MR. The single mutation S810L in the LBD leads to a constant MR activation. The inheritance is autosomal dominant. The disease is characterized by the onset of severe hypertension before the age of 20, with severe exacerbation in pregnancy.