CHARACTERIZATION OF A CHIMERIC HD(3) D(2) DOPAMINE RECEPTOR EXPRESSEDIN CHO CELLS/

The D2 dopamine receptor is known to be functionally coupled when expr essed in CHO cells, whereas the effector systems for the D3 dopamine r eceptor remain unclear. A chimeric, human D3/D2 receptor (hD3/D2) was constructed containing the third intracellular loop region of the D2 r eceptor. CHO cells stably expressing the D2, D3, or hD3/D2 receptors w ere created and the pharmacology of the receptors was examined. The ch imeric hD3/D2 receptor retained D3-like affinities for dopaminergic li gands. However, in contrast to the D2 receptor neither the D3 receptor nor the hD3/D2 receptor could functionally couple to the adenylate cy clase or arachidonic acid release mechanisms.