title: G protein-coupled receptor kinase 5 regulates beta 1-adrenergic receptor association with PSD-95.
abstract: We previously reported that the beta(1)-adrenergic receptor (beta(1)AR) associates with PSD-95 through a PDZ domain-mediated interaction, by which PSD-95 modulates beta(1)AR function and facilitates the physical association of beta(1)AR with other synaptic proteins such as N-methyl-d-aspartate receptors. Here we demonstrate that beta(1)AR association with PSD-95 is regulated by G protein-coupled receptor kinase 5 (GRK5). When beta(1)AR and PSD-95 were coexpressed with either GRK2 or GRK5 in COS-7 cells, GRK5 alone dramatically decreased the association of beta(1)AR with PSD-95, although GRK2 and GRK5 both could be co-immunoprecipitated with beta(1)AR and both could enhance receptor phosphorylation in vivo. Increasing expression of GRK5 in the cells led to further decreased beta(1)AR association with PSD-95. Stimulation with the beta(1)AR agonist isoproterenol further decreased PSD-95 binding to beta(1)AR. In addition, GRK5 protein kinase activity was required for this regulatory effect since a kinase-inactive GRK5 mutant had no effect on PSD-95 binding to beta(1)AR. Moreover, the regulatory effect of GRK5 on beta(1)AR association with PSD-95 was observed only when GRK5 was expressed together with the receptor, but not when GRK5 was coexpressed with PSD-95. Thus, we propose that GRK5 regulates beta(1)AR association with PSD-95 through phosphorylation of beta(1)AR. Regulation of protein association through receptor phosphorylation may be a general mechanism used by G protein-coupled receptors that associate via PDZ domain-mediated protein/protein interactions.
authors.affiliation: Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: Liaoyuan A
authors.initials: LA
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Richard T
authors.initials: RT
authors.lastname: Premont
authors.forename: Mei
authors.initials: M
authors.lastname: Cong
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lefkowitz
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D019390:Arrestins / Q000235:genetics / Q000378:metabolism; D019556:COS Cells; D016895:Culture Media, Serum-Free; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D054774:G-Protein-Coupled Receptor Kinase 5; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014162:Transfection; D051552:beta-Adrenergic Receptor Kinases; D000071557:beta-Arrestins
chemical_list: D000318:Adrenergic beta-Agonists; D019390:Arrestins; D016895:Culture Media, Serum-Free; D009419:Nerve Tissue Proteins; D018342:Receptors, Adrenergic, beta-1; D011993:Recombinant Fusion Proteins; D000071557:beta-Arrestins; C033652:postsynaptic density proteins; D017346:Protein Serine-Threonine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D051552:beta-Adrenergic Receptor Kinases; D054774:G-Protein-Coupled Receptor Kinase 5; D019204:GTP-Binding Proteins; D007545:Isoproterenol