Interactions between the dopamine D2 receptor and GTP-binding proteins.
The dopamine D2 receptor in bovine brain striatum exists in a high- and a low-affinity state for dopamine. The high-affinity state is believed to arise from coupling with a guanine nucleotide-binding protein, to be disrupted by the addition of GTP. We found that antibodies specific to the C-terminal region of the alpha-subunit of Go and Gi cause a shift from high- towards low-affinity, demonstrating that the C-terminus of G alpha is involved in the receptor G protein contact. Purification of the D2 receptor by affinity chromatography via immobilized agonists or antagonists results in the copurification of both Go and Gi proteins. However, this copurification is of a nonspecific nature and prevents the detection of putative specific receptor.G protein complexes.
Plug
M J
MJ
Sylvius Laboratory, University of Leiden, The Netherlands.
Möller
W
W
Dijk
J
J
D000818:Animals; D000906:Antibodies; D001667:Binding, Competitive; D002417:Cattle; D003342:Corpus Striatum / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D011485:Protein Binding; D017448:Receptors, Dopamine D2 / Q000302:isolation & purification / Q000378:metabolism*; D013134:Spiperone / Q000378:metabolism
D000906:Antibodies; D017448:Receptors, Dopamine D2; D013134:Spiperone; D019204:GTP-Binding Proteins; D004298:Dopamine