Activation by G protein beta gamma subunits of beta-adrenergic and muscarinic receptor kinase.
We have shown previously that GTP-binding regulatory protein (G protein) beta gamma subunits stimulate the agonist- or light-dependent phosphorylation of muscarinic acetylcholine receptors (mAChRs) and rhodopsin by a protein kinase partially purified from porcine brain (mAChR kinase) but not the phosphorylation of rhodopsin by rhodopsin kinase (Haga, K., and Haga, T. (1992) J. Biol. Chem. 267, 2222-2227). We report here that the mAChR kinase phosphorylates beta-adrenergic receptors (beta-ARs) purified from bovine lung in an agonist-dependent manner, and the phosphorylation is also stimulated by G protein beta gamma subunits. We also report that recombinant beta-adrenergic receptor kinase 1 (beta-ARK1) expressed in COS-7 cells phosphorylates mAChRs (human m2 subtype) and rhodopsin in an agonist- or light-dependent manner, respectively, and that this phosphorylation is stimulated by G protein beta gamma subunits. By contrast, the beta gamma subunits do not stimulate the phosphorylation of mAChRs or rhodopsin by a beta-ARK1 mutant lacking a part of the carboxyl-terminal region which is present in beta-ARKs but not in rhodopsin kinase. These results indicate that the beta-ARK1 is the same as or very similar to the mAChR kinase but is distinguished from the rhodopsin kinase with respect to activation by the beta gamma subunits and that the extra carboxyl-terminal sequence in beta-ARKs is required for the stimulation by the beta gamma subunits.
Kameyama
K
K
Department of Biochemistry, Faculty of Medicine, University of Tokyo, Japan.
Haga
K
K
Haga
T
T
Kontani
K
K
Katada
T
T
Fukada
Y
Y
D000526:Alprenolol / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001483:Base Sequence; D002217:Carbachol / Q000494:pharmacology; D002417:Cattle; D002460:Cell Line; D017868:Cyclic AMP-Dependent Protein Kinases; D004789:Enzyme Activation; D054769:G-Protein-Coupled Receptor Kinase 2; D019204:GTP-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D005822:Genetic Vectors; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D008168:Lung / Q000378:metabolism; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012243:Rhodopsin / Q000302:isolation & purification / Q000378:metabolism; D014162:Transfection; D051552:beta-Adrenergic Receptor Kinases
D046911:Macromolecular Substances; D009838:Oligodeoxyribonucleotides; D011976:Receptors, Muscarinic; D011994:Recombinant Proteins; D001285:Atropine; D000526:Alprenolol; D002217:Carbachol; D012243:Rhodopsin; D011494:Protein Kinases; D020794:Receptor Protein-Tyrosine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D051552:beta-Adrenergic Receptor Kinases; C080577:muscarinic receptor kinase; D054769:G-Protein-Coupled Receptor Kinase 2; D019204:GTP-Binding Proteins; D007545:Isoproterenol