MOLECULAR DETERMINANTS OF THE ALPHA-2D ADRENERGIC-RECEPTOR SUBTYPE

The alpha-2 adrenergic receptor in the bovine pineal gland and the rod ent homologues of the human alpha-2-C10 receptor express alpha-2D subt ype pharmacological characteristics. The alpha-2 adrenergic receptor i n the chicken pineal expresses characteristics similar to the alpha-2A subtype found in human and pig. The rodent receptors (alpha-2D) conta in a serine residue at position 201 whereas the human and porcine rece ptors (alpha-2A) have a cysteine at this position. Our results indicat e that the bovine pineal receptor has a serine at position 201, suppor ting the alpha-2D classification. However, the chicken pineal receptor also contains a serine at position 201 suggesting that other amino ac ids may be responsible for the differences in pharmacological characte ristics.