Heterologous desensitization of turkey erythrocyte β‐adrenoceptors correlates with receptor phosphorylation and impaired receptor‐Gs coupling, as assessed by fusion of purified desensitized receptors with X. laevis erythrocytes [(1984) Science 225, 837‐840]. We have purified β‐receptors from desensitized and untreated turkey erythrocytes and have compared the abilities of these two receptors to couple with pure turkey erythrocyte Gs in a reconstituted system. Functional receptor‐Gs coupling was assessed by measuring hormone‐dependent (i) Gs, activation by GTPγS and (ii) GTPase activity. While in membranes prepared from desensitized cells, receptor‐Gs, coupling was clearly reduced, this effect was absent when coupling of purified desensitized receptor was measured. We conclude that covalent modification by phosphorylation does not fully explain the functional uncoupling at the membrane level.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.