Dopamine receptors are classified into D1 and D2 subtypes on the basis of their pharmacological and biochemical characteristics1,2. The D2 dopamine receptor has been implicated in the pathophysiology and treatment of movement disorders3, schizophrenia4 and drug addiction5. The D2 dopamine receptor interacts with guanine nucleotide-binding proteins to induce second messenger systems6,7. Other members of the family of receptors that are coupled to G proteins share a significant similarity in primary amino-acid sequence and exhibit an archetypical topology predicted to consist of seven putative transmembrane domains8. We have taken advantage of the expected nucleotide sequence similarities among members of this gene family to isolate genes coding for new receptors. Using the hamster β2-adrenergic receptor gene as a hybridization probe we have isolated related genes including a cDNA encoding the rat D2 dopamine receptor. This receptor has been characterized on the basis of three criteria: the deduced amino-acid sequence which reveals that it is a member of the family of G-protein-coupled receptors; the tissue distribution of the mRNA which parallels that of the D2 dopamine receptor; and the pharmacological profile of mouse fibroblast cells transfected with the cDNA.
ASJC Scopus subject areas