IDENTIFICATION OF A SPLICE VARIANT OF THE RAT AND HUMAN MINERALOCORTICOID RECEPTOR GENES

The sequence of a splice variant of the rat mineralocorticoid receptor (MR) gene is presented. A cDNA clone corresponding to rat MR was isol ated from a rat brain cDNA library. Sequence analysis of the region co rresponding to the DNA binding domain revealed the presence of a 12 ba se pair (bp) insertion. Analysis of mRNA from several rat tissues sugg ests that the variant is less abundant than the wild type in most tiss ues. The insertion variant is also a product of the human MR gene, the identical splice variant was also observed in human white blood cell mRNA. Unlike other splice variants reported for the MR, this variant a lters the encoded protein by the addition of four amino acid residues in the DNA binding domain. The altered protein may influence the affin ity of the MR for mineralocorticoid or glucocorticoid response element s.