title: Interaction with receptor for activated C-kinase 1 (RACK1) sensitizes the phosphodiesterase PDE4D5 towards hydrolysis of cAMP and activation by protein kinase C.
abstract: We have previously identified the PKC (protein kinase C)-anchoring protein RACK1 (receptor for activated C-kinase 1), as a specific binding partner for the cAMP-specific phosphodiesterase PDE4D5, suggesting a potential site for cross-talk between the PKC and cAMP signalling pathways. In the present study we found that elevation of intracellular cAMP, with the β₂-adrenoceptor agonist isoproterenol (isoprenaline), led to activation of PDE4 enzymes in the particulate and soluble fractions of HEK (human embryonic kidney)-293 cells. In contrast activation of PDE4D5, with isoproterenol and the PKC activator PMA, was restricted to the particulate fraction, where it interacts with RACK1; however, RACK1 is dispensable for anchoring PDE4D5 to the particulate fraction. Kinetic studies demonstrated that RACK1 alters the conformation of particulate-associated PDE4D5 so that it more readily interacts with its substrate cAMP and with rolipram, a PDE4 inhibitor that specifically targets the active site of the enzyme. Interaction with RACK1 was also essential for PKC-dependent and ERK (extracellular-signal-regulated kinase)-independent phosphorylation (on Ser¹²⁶), and activation of PDE4D5 in response to PMA and isoproterenol, both of which trigger the recruitment of PKCα to RACK1. Together these results reveal novel signalling cross-talk, whereby RACK1 mediates PKC-dependent activation of PDE4D5 in the particulate fraction of HEK-293 cells in response to elevations in intracellular cAMP.
authors.affiliation: Institute of Molecular Cell and Systems Biology, University of Glasgow, Scotland, UK.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Bird
authors.forename: George S
authors.initials: GS
authors.lastname: Baillie
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Yarwood
mesh_terms: D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D000242:Cyclic AMP / Q000378:metabolism*; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3 / Q000235:genetics / Q000378:metabolism*; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D004789:Enzyme Activation / Q000187:drug effects; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D006868:Hydrolysis; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D058988:Phosphodiesterase 4 Inhibitors / Q000494:pharmacology; D010766:Phosphorylation; D011485:Protein Binding / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism*; D051571:Protein Kinase C-alpha / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D020889:Rolipram / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection
chemical_list: D009363:Neoplasm Proteins; D058988:Phosphodiesterase 4 Inhibitors; C419368:RACK1 protein, human; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D000242:Cyclic AMP; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; C517376:PDE4D protein, human; D019204:GTP-Binding Proteins; D020889:Rolipram; D007545:Isoproterenol; D013755:Tetradecanoylphorbol Acetate
references.citation: Chem Rev. 2001 Aug;101(8):2381-411
references.pmid: 11749379
references.citation: Cancer Res. 1988 Jan 1;48(1):1-8
references.pmid: 3275491
references.citation: Methods Mol Biol. 1998;87:25-39
references.pmid: 9523256
references.citation: J Immunol Methods. 2002 Sep 1;267(1):13-26
references.pmid: 12135797
references.citation: J Biol Chem. 2003 Feb 21;278(8):5493-6
references.pmid: 12493749
references.citation: Cell Signal. 2007 Dec;19(12):2612-24
references.pmid: 17900862
references.citation: J Biol Chem. 1999 May 21;274(21):14909-17
references.pmid: 10329691
references.citation: J Biol Chem. 2005 Sep 30;280(39):33178-89
references.pmid: 16030021
references.citation: Am J Physiol Gastrointest Liver Physiol. 2008 Jan;294(1):G327-35
references.pmid: 18006600
references.citation: Mol Pharmacol. 2002 Dec;62(6):1261-73
references.pmid: 12435793
references.citation: J Biol Chem. 2009 Jun 26;284(26):17391-403
references.pmid: 19423709
references.citation: Structure. 2003 Jul;11(7):865-73
references.pmid: 12842049
references.citation: Neuropharmacology. 2001;40(2):262-9
references.pmid: 11114405
references.citation: Science. 2002 Oct 25;298(5594):834-6
references.pmid: 12399592
references.citation: Adv Pharmacol. 1998;44:225-342
references.pmid: 9547887
references.citation: BMC Biochem. 2002 Aug 23;3:24
references.pmid: 12193273
references.citation: Mol Cell Biol. 2006 Jun;26(11):4041-51
references.pmid: 16705158
references.citation: Nature. 1970 Aug 15;227(5259):680-5
references.pmid: 5432063
references.citation: Nature. 1988 Aug 11;334(6182):494-8
references.pmid: 2900470
references.citation: Biochem Soc Trans. 2007 Nov;35(Pt 5):938-41
references.pmid: 17956250
references.citation: J Biol Chem. 1999 Jul 9;274(28):19677-85
references.pmid: 10391907
references.citation: Cell Immunol. 1976 Nov;27(1):1-10
references.pmid: 186194
references.citation: J Biol Chem. 2003 Dec 5;278(49):49230-8
references.pmid: 14500724
references.citation: Br J Pharmacol. 2009 Sep;158(1):70-86
references.pmid: 19210747
references.citation: Mol Pharmacol. 2001 Nov;60(5):1100-11
references.pmid: 11641439
references.citation: Nature. 1993 Jul 15;364(6434):249-52
references.pmid: 8321321
references.citation: Biochem J. 2006 Mar 1;394(Pt 2):427-35
references.pmid: 16356165
references.citation: J Biol Chem. 2008 Aug 22;283(34):22952-61
references.pmid: 18567578
references.citation: FASEB J. 1998 Jan;12(1):35-42
references.pmid: 9438408
references.citation: J Biol Chem. 2009 Jul 24;284(30):20263-74
references.pmid: 19423701
references.citation: Biochem J. 1997 Dec 1;328 ( Pt 2):539-48
references.pmid: 9371713
references.citation: Biochem J. 2003 Feb 15;370(Pt 1):1-18
references.pmid: 12444918
references.citation: Biochem J. 2006 Aug 15;398(1):23-36
references.pmid: 16689683
references.citation: Drug Discov Today. 2005 Nov 15;10(22):1503-19
references.pmid: 16257373
references.citation: Pharmacol Ther. 2006 Mar;109(3):366-98
references.pmid: 16102838