title: beta-Arrestin-mediated PDE4 cAMP phosphodiesterase recruitment regulates beta-adrenoceptor switching from Gs to Gi.
abstract: Phosphorylation of the beta(2) adrenoreceptor (beta(2)AR) by cAMP-activated protein kinase A (PKA) switches its predominant coupling from stimulatory guanine nucleotide regulatory protein (G(s)) to inhibitory guanine nucleotide regulatory protein (G(i)). beta-Arrestins recruit the cAMP-degrading PDE4 phosphodiesterases to the beta(2)AR, thus controlling PKA activity at the membrane. Here we investigate a role for PDE4 recruitment in regulating G protein switching by the beta(2)AR. In human embryonic kidney 293 cells overexpressing a recombinant beta(2)AR, stimulation with isoprenaline recruits beta-arrestins 1 and 2 as well as both PDE4D3 and PDE4D5 to the receptor and stimulates receptor phosphorylation by PKA. The PKA phosphorylation status of the beta(2)AR is enhanced markedly when cells are treated with the selective PDE4-inhibitor rolipram or when they are transfected with a catalytically inactive PDE4D mutant (PDE4D5-D556A) that competitively inhibits isoprenaline-stimulated recruitment of native PDE4 to the beta(2)AR. Rolipram and PDE4D5-D556A also enhance beta(2)AR-mediated activation of extracellular signal-regulated kinases ERK12. This is consistent with a switch in coupling of the receptor from G(s) to G(i), because the ERK12 activation is sensitive to both inhibitors of PKA (H89) and G(i) (pertussis toxin). In cardiac myocytes, the beta(2)AR also switches from G(s) to G(i) coupling. Treating primary cardiac myocytes with isoprenaline induces recruitment of PDE4D3 and PDE4D5 to membranes and activates ERK12. Rolipram robustly enhances this activation in a manner sensitive to both pertussis toxin and H89. Adenovirus-mediated expression of PDE4D5-D556A also potentiates ERK12 activation. Thus, receptor-stimulated beta-arrestin-mediated recruitment of PDE4 plays a central role in the regulation of G protein switching by the beta(2)AR in a physiological system, the cardiac myocyte.
authors.affiliation: Molecular Pharmacology Group, Division of Biochemistry and Molecular Biology, Institute for Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors.forename: George S
authors.initials: GS
authors.lastname: Baillie
authors.forename: Arvind
authors.initials: A
authors.lastname: Sood
authors.forename: Ian
authors.initials: I
authors.lastname: McPhee
authors.forename: Irene
authors.initials: I
authors.lastname: Gall
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Perry
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lefkowitz
authors.forename: Miles D
authors.initials: MD
authors.lastname: Houslay
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D019390:Arrestins / Q000378:metabolism*; D002460:Cell Line; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005799:Genes, Dominant; D049452:Green Fluorescent Proteins; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D008164:Luminescent Proteins / Q000378:metabolism; D008954:Models, Biological; D009206:Myocardium / Q000166:cytology; D037342:Pertussis Toxin / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D020889:Rolipram / Q000494:pharmacology; D015398:Signal Transduction; D013449:Sulfonamides; D013997:Time Factors; D014162:Transfection; D000071557:beta-Arrestins
chemical_list: D019390:Arrestins; D004791:Enzyme Inhibitors; D007546:Isoquinolines; D008164:Luminescent Proteins; D011943:Receptors, Adrenergic, beta; D013449:Sulfonamides; D000071557:beta-Arrestins; D049452:Green Fluorescent Proteins; D000242:Cyclic AMP; D037342:Pertussis Toxin; D017868:Cyclic AMP-Dependent Protein Kinases; D010727:Phosphoric Diester Hydrolases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; C517376:PDE4D protein, human; D020889:Rolipram; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide