Isolation and expression of rat 1,25-dihydroxyvitamin D3 receptor cDNA

The cDNA for the 1,25-dihydroxyvitamin D3 receptor has been isolated by screening a rat kidney lambda gt11 expression library with a mixture of three previously identified anti-receptor monoclonal antibodies. Protein produced from this cDNA reacts with each of the three monoclonal antibodies but does not react with an antibody specific for the porcine receptor or an irrelevant antibody. In addition, the expressed protein specifically binds 1,25-dihydroxyvitamin D3 but does not bind estradiol, progesterone, testosterone, cortisol, or aldosterone. The nucleotide sequence for this cDNA has been determined and used to deduce the amino acid sequence of the protein. This amino acid sequence contains a region that matches perfectly the partial amino acid sequence determined for the receptor isolated from porcine intestine. This amino acid sequence also closely matches the reported amino acid sequence of the putative DNA-binding finger of the avian 1,25-dihydroxyvitamin D3 receptor.