Isolation of turkey adrenocortical cell angiotensin II (AII) receptor partial cDNA: Evidence for a single-copy gene expressed predominantly in the adrenal gland

A turkey adrenocortical cell AII receptor cDNA fragment (714 bp) was isolated by RT-PCR using oligonucleotide primers based on rat aortic smooth muscle (RASM) and bovine adrenal type-1 (AT₁) receptor cDNA coding sequences as primers. Sequence analysis indicated 73% nucleotide identity and 78% amino acid identity to the RASM AT₁ receptor. Notable differences were 1) two additional Cys at positions 92 and 99 (first extracellular loop), 2) deletion of amino acid 168, formation of a triplet Asn sequence (Asn^{186, 187, 188}) and substitution of Arg¹⁹² with Pro (second extracellular loop) and 3) two additional potential protein kinase C phosphorylation sites, Thr²²¹ and Thr²³³ (third intracellular loop). Southern blot analysis indicated that the receptor is a product of a single- copy gene. Northern blot analysis indicated at least three mRNA transcripts (7.5, 3.5 and 2.0 kb) expressed predominantly in the adrenal gland.