title: The beta-adrenergic receptor kinase interacts with the amino terminus of the G protein beta subunit.
abstract: Desensitization of G protein-coupled receptors involves phosphorylation of the receptors by G protein-coupled receptor kinases, such as the beta-adrenergic receptor kinase (beta ARK). beta ARK activity depends upon its translocation from the cytoplasm to the membrane. The beta gamma subunits of G proteins bind to beta ARK and recruit the kinase to the membrane. The G beta gamma binding domain is localized to a carboxyl terminal region of beta ARK but the beta ARK binding domain of G beta gamma is not known. We used the yeast two-hybrid assay to characterize the interaction between G beta and beta ARK. We demonstrate an interaction between the carboxyl terminus of beta ARK and G beta 2. The strength of this interaction is increased when the VP16 transactivation domain is placed on the carboxyl end of G beta 2, indicating that an accessible G beta 2 amino terminus is important for its interaction with beta ARK. In addition, we show that amino acids 1 to 145 of G beta 2 are sufficient for beta ARK binding.
authors.affiliation: Vollum Institute, Oregon Health Sciences University, Portland 97201, USA. goldmanp@ohsu.edu
authors.forename: P S
authors.initials: PS
authors.lastname: Goldman
authors.forename: A J
authors.initials: AJ
authors.lastname: DeMaggio
authors.forename: M F
authors.initials: MF
authors.lastname: Hoekstra
authors.forename: R H
authors.initials: RH
authors.lastname: Goodman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D003001:Cloning, Molecular; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D046911:Macromolecular Substances; D010446:Peptide Fragments / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D015533:Transcriptional Activation; D051552:beta-Adrenergic Receptor Kinases
chemical_list: D046911:Macromolecular Substances; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D017868:Cyclic AMP-Dependent Protein Kinases; D051552:beta-Adrenergic Receptor Kinases; D019204:GTP-Binding Proteins