CHARACTERIZATION OF SUBTYPE-SPECIFIC ANTIBODIES TO THE HUMAN D-5 DOPAMINE-RECEPTOR - STUDIES IN PRIMATE BRAIN AND TRANSFECTED MAMMALIAN-CELLS

To achieve a better understanding of how D-5 dopamine receptors mediate the actions of dopamine in brain, we have developed antibodies specific for the D-5 receptor. D-5 antibodies reacted with recombinant baculovirus-infected Sf9 cells expressing the D-5 receptor but not with the D-1 receptor or a variety of other catecholaminergic and muscarinic receptors. Epitope-tagged D-5 receptors expressed in mammalian cells were reactive with both D-5 antibodies and an epitope-specific probe. A mixture of N-linked glycosylated polypeptides and higher molecular-mass species was detected on immunoblots of membrane fractions of D-5-transfected cells and also of primate brain. D-5 receptor antibodies intensely labeled pyramidal neurons in the prefrontal cortex, whereas spiny medium-sized neurons and aspiny large interneurons of the caudate nucleus were relatively lightly labeled. Antibodies to the D-5 dopamine receptor should prove important in experimentally determining specific roles for the D-5 and D-1 receptors in cortical processes and diseases.