Molecular Cloning of a Mineralocorticoid (Type I) Receptor Complementary DNA from Rat Hippocampus

Abstract

Rat brain expresses two types of corticosteroid-binding proteins. The type I receptor binds corticosterone with high affinity and is structurally related to the kidney mineralocorticoid receptor (MR), while the type II or classical glucocorticoid receptor binds corticosterone with lower affinity and displays an in vivo preference for dexamethasone. Here we describe the isolation and characterization of a cDNA coding for the MR, from a rat hippocampus cDNA library, by low stringency hybridization to radiolabeled human glucocorticoid receptor cDNA. The nucleotide and deduced amino acid sequence for rat hippocampal MR displays extensive homology to a MR cDNA isolated from human kidney, suggesting that they are orthologous genes. Southern analysis suggests that there is only one gene for the MR, and in vitro expression of the receptor generates a high affinity corticosterone-binding protein. These data provide evidence to support the contention that a single gene gives rise to the MR in renal tissues and type I receptors in the brain.

Nuclear Receptors and Their Selective Pharmacologic Modulators

“…On the basis of the predicted amino acid sequence and domain structure of the receptor, the location of the DNA-binding domain (DBD) and steroid-binding domain (ligand-binding domain; LBD) was correctly predicted (Weinberger et al, 1985b). The cDNAs for all of the steroid receptors were rapidly identified, including the estrogen receptor (ER) (Walter et al, 1985;Green et al, 1986;Greene et al, 1986;Krust et al, 1986;Kumar et al, 1986), the progesterone receptor (PR) (Conneely et al, 1986(Conneely et al, , 1987aJeltsch et al, 1986;Loosfelt et al, 1986;Gronemeyer et al, 1987;Misrahi et al, 1987), the mineralocorticoid receptor (MR) (Arriza et al, 1987;Patel et al, 1989), and the androgen receptor (AR) (Chang et al, 1988a,b;Lubahn et al, 1988;Trapman et al, 1988;Tilley et al, 1989). Comparison of the sequences of all of these receptors demonstrated a highly conserved structure that was defined as six subregions (regions A through F; Fig.…”

Glucocorticoid and mineralocorticoid regulation of angiotensin II type 1 receptor binding and inositol triphosphate formation in WB cells

“…Amplification was performed over 30 cycles (30 s denaturing at 94 C, 1 min annealing at 58 C, 1 min extension at 72 C) in a DNA thermal cycler (Perkin Elmer Cetus). The 5 and 3 MR primers correspond to bp 4875-4901 and bp 5550-5524, respectively, of the rat MR mRNA coding sequence as described elsewhere (Patel et al 1989). The identity of the amplified MR RT-PCR product (695 bp) was confirmed by EcoR1 restriction enzyme cleavage.…”

11β‐hydroxysteroid dehydrogenase isoforms and their implications for blood pressure regulation

“…By contrast, MR in the distal nephron selectively bind aldosterone in zho, despite a vast (-1000-fold) molar excess of circulating glucocorticoid. This aldosterone-selectivity in civo cannot be ascribed to variations in the structure of renal MR as these are identical to MR in the heart and hippocampus where both aldosterone and corticosterone bind avidly in uivo [3,7]. Nor can tissue or plasma sequestration of glucocorticoids by corticosteroid-binding globulins explain this paradox, as aldosterone also selectively binds to renal MR in tlivo in neonatal animals which are relatively deficient in binding proteins [8].…”