title: Carboxyl terminal domain of Gs alpha specifies coupling of receptors to stimulation of adenylyl cyclase.
abstract: The alpha subunits of Gs and Gi link different sets of hormone receptors to stimulation and inhibition, respectively, of adenylyl cyclase. A chimeric alpha i/alpha s cDNA was constructed that encodes a polypeptide composed of the amino terminal 60% of an alpha i chain and the carboxyl terminal 40% of alpha s. The cDNA was introduced via a retroviral vector into S49 cyc- cells, which lack endogenous alpha s. Although less than half of the hybrid alpha chain is derived from alpha s, its ability to mediate beta-adrenoceptor stimulation of adenylyl cyclase matched that of the normal alpha s polypeptide expressed from the same retroviral vector in cyc- cells. This result indicates that carboxyl terminal amino acid sequences of alpha s contain the structural features that are required for specificity of interactions with the effector enzyme, adenylyl cyclase, as well as with the hormone receptor.
mesh_terms: D000262:Adenylyl Cyclases / Q000502:physiology*; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D002772:Cholera Toxin / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000502:physiology*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D051379:Mice; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D011994:Recombinant Proteins; D013004:Somatostatin / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D011943:Receptors, Adrenergic, beta; D011994:Recombinant Proteins; D005576:Colforsin; D013004:Somatostatin; D006160:Guanosine Triphosphate; D002772:Cholera Toxin; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D007545:Isoproterenol