Merck Millipore Membrane Preparation Recombinant Human Dopamine Receptor

Dopamine is a catecholamine neurotransmitter that functions in the CNS to control locomotor, cognitive, emotional and neurendocrine processes, and in the periphery to modulate cardiovascular, renal and gastrointestinal processes. The biological activities of dopamine are mediated by a family of five GPCRs. The D1 and D5 subtypes couple to Gs to increase intracellular cAMP, whereas the D2, D3 and D4 subtypes couple to Gi to reduce cAMP (Missale et al., 1998). The D2 dopamine receptors have been of particular clinical interest due to their regulation of prolactin secretion and their affinity for antipsychotic drugs. The D2 receptor exists as two alternatively spliced isoforms differing in the insertion of a stretch of 29 amino acids in the third intracellular loop (D2S and D2L) (Giros et al., 1989; Grandy et al., 1989). Millipore's D2 dopamine membrane preparations are crude membrane preparations made from our proprietary stable recombinant cell lines to ensure high-level of GPCR surface expression; thus, they are ideal HTS tools for screening of antagonists of D2 dopamine receptor interactions with its ligand. The membrane preparations exhibit a Kd of 0.51nM for [125I]-Iodospiperone. With 5.0 ug/well D2 Dopamine Membrane Prep and 0.1nM [125I]-Iodospiperone, a greater than 10-fold signal-to-background ratio was obtained.