Coupling of D2 dopamine receptors to G-proteins in solubilized preparations of bovine caudate nucleus.
1. The coupling of D2 dopamine receptors and G-proteins has been examined in cholate-solubilized preparations of bovine caudate nucleus. 2. No receptor-G-protein coupling could be detected in solubilized preparations obtained in 0.3% cholate, but if this preparation is diluted 5-fold, coupling is re-established. 3. The dilution process was examined, and it was shown that the change in ionic strength was an important factor in modulating the observed receptor-G-protein interaction. 4. Ionic strength was shown, however, not to be the primary determinant of receptor-G-protein coupling. This is likely to be the formation, upon dilution of the preparation, of vesicles in which receptor and G-protein reassociate. 5. The formation of vesicles upon dilution was examined by a variety of techniques, including thermal-stability studies, gel filtration, centrifugation and electron microscopy.
Chazot
J A
JA
Biological Laboratory, University of Kent, Canterbury, U.K.
Strange
P G
PG
D000818:Animals; D001667:Binding, Competitive; D002417:Cattle; D002421:Caudate Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D002850:Chromatography, Gel; D019204:GTP-Binding Proteins / Q000378:metabolism*; D007700:Kinetics; D008854:Microscopy, Electron; D011954:Receptors, Dopamine / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology; D012995:Solubility; D013134:Spiperone / Q000378:metabolism; D013696:Temperature
D011954:Receptors, Dopamine; D012965:Sodium Chloride; D013134:Spiperone; D019204:GTP-Binding Proteins