Activation of Cyclic AMP-Dependent Protein Kinase Inhibits the Desensitization and Internalization of Metabotropic Glutamate Receptors 1a and 1b
Open Access
- 1 June 2004
- journal article
- Published by Elsevier in Molecular Pharmacology
- Vol. 65 (6) , 1507-1516
- https://doi.org/10.1124/mol.65.6.1507
Abstract
In this study, we characterized the effects of activation of cyclic AMP-dependent protein kinase (PKA) on the internalization and functional coupling of the metabotropic glutamate receptor (mGluR1) splice variants mGluR1a and mGluR1b. Using an enzyme-linked immunosorbent assay technique to assess receptor internalization, we found that the glutamate-induced internalization of mGluR1a or mGluR1b transiently expressed in human embryonic kidney (HEK) 293 cells was inhibited by coactivation of endogenous β2-adrenoceptors with isoprenaline or by direct activation of adenylyl cyclase with forskolin. The PKA inhibitor N-(2-[p-bromocinnamylamino]ethyl)-5-isoquinolinesulfonamide hydrochloride (H89) blocked the effects of both isoprenaline and forskolin. The heterologous internalization of the mGluR1 splice variants triggered by carbachol was also inhibited by isoprenaline and forskolin in a PKA-sensitive fashion, whereas the constitutive (agonist-independent) internalization of mGluR1a was inhibited only modestly by PKA activation. Using inositol phosphate (IP) accumulation in cells prelabeled with [3H]inositol to assess receptor coupling, PKA activation increased basal IP accumulation in mGluR1a receptor-expressing cells and also increased glutamate-stimulated IP accumulation in both mGluR1a- and mGluR1b-expressing cells, but only at short times of glutamate addition. Furthermore, PKA activation completely blocked the carbachol-induced heterologous desensitization of glutamate-stimulated IP accumulation in both mGluR1a- and mGluR1b-expressing cells. In coimmunoprecipitation experiments, the ability of glutamate to increase association of GRK2 and arrestin-2 with mGluR1a and mGluR1b was inhibited by PKA activation with forskolin. Together, these results indicate that PKA activation inhibits the agonist-induced internalization and desensitization of mGluR1a and mGluR1b, probably by reducing their interaction with GRK2 and nonvisual arrestins.Keywords
This publication has 27 references indexed in Scilit:
- Desensitization and Internalization of Metabotropic Glutamate Receptor 1a Following Activation of Heterologous Gq/11-Coupled ReceptorsBiochemistry, 2004
- Role of G Protein-coupled Receptor Kinase 4 and ॆ-Arrestin 1 in Agonist-stimulated Metabotropic Glutamate Receptor 1 Internalization and Activation of Mitogen-activated Protein KinasesJournal of Biological Chemistry, 2003
- Differential Roles of Arrestin-2 Interaction with Clathrin and Adaptor Protein 2 in G Protein-coupled Receptor TraffickingJournal of Biological Chemistry, 2002
- Cyclic AMP–dependent protein kinase phosphorylation facilitates GABAB receptor–effector couplingNature Neuroscience, 2002
- Agonist-Stimulated and Tonic Internalization of Metabotropic Glutamate Receptor 1a in Human Embryonic Kidney 293 Cells: Agonist-Stimulated Endocytosis Is β-Arrestin1 Isoform-SpecificMolecular Pharmacology, 2001
- Regulation of Membrane Targeting of the G Protein-coupled Receptor Kinase 2 by Protein Kinase A and Its Anchoring Protein AKAP79Journal of Biological Chemistry, 2001
- G Protein-coupled Receptor Kinase-mediated Desensitization of Metabotropic Glutamate Receptor 1A Protects against Cell DeathPublished by Elsevier ,2000
- Selective Regulation of Endogenous G Protein-coupled Receptors by Arrestins in HEK293 CellsPublished by Elsevier ,2000
- THE ROLE OF RECEPTOR KINASES AND ARRESTINS IN G PROTEIN–COUPLED RECEPTOR REGULATIONAnnual Review of Pharmacology and Toxicology, 1998
- β-Arrestin acts as a clathrin adaptor in endocytosis of the β2-adrenergic receptorNature, 1996