HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 279, Issue 51, 53806-53817, December 17, 2004

This Article Full Text Full Text (PDF) All Versions of this Article: 279/51/53806    most recent M407676200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Holst, B. Articles by Schwartz, T. W. Search for Related Content PubMed PubMed Citation Articles by Holst, B. Articles by Schwartz, T. W. Social Bookmarking                      What's this?

Common Structural Basis for Constitutive Activity of the Ghrelin Receptor Family^*

Birgitte Holst, Nicholas D. Holliday¶, Anders Bach, Christian E. Elling||, Helen M. Cox¶, and Thue W. Schwartz||

From the Laboratory for Molecular Pharmacology, Department of Pharmacology, The Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen, Denmark, ^¶Centre for Neuroscience Research, King's College London, Guy's Campus, London, SE1 1UL, United Kingdom, and ^||7TM Pharma A/S, Fremtidsvej 3, DK-2970, Hørsholm, Denmark

Three members of the ghrelin receptor family were characterized in parallel: the ghrelin receptor, the neurotensin receptor 2 and the orphan receptor GPR39. In transiently transfected COS-7 and human embryonic kidney 293 cells, all three receptors displayed a high degree of ligand-independent signaling activity. The structurally homologous motilin receptor served as a constitutively silent control; upon agonist stimulation, however, it signaled with a similar efficacy to the three related receptors. The constitutive activity of the ghrelin receptor and of neurotensin receptor 2 through the G_q, phospholipase C pathway was 50% of their maximal capacity as determined through inositol phosphate accumulation. These two receptors also showed very high constitutive activity in activation of cAMP response element-driven transcription. GPR39 displayed a clear but lower degree of constitutive activity through the inositol phosphate and cAMP response element pathways. In contrast, GPR39 signaled with the highest constitutive activity in respect of activation of serum response element-dependent transcription, in part, possibly, through G_12/13 and Rho kinase. Antibody feeding experiments demonstrated that the epitope-tagged ghrelin receptor was constitutively internalized but could be trapped at the cell surface by an inverse agonist, whereas GPR39 remained at the cell surface. Mutational analysis showed that the constitutive activity of both the ghrelin receptor and GPR39 could systematically be tuned up and down depending on the size and hydrophobicity of the side chain in position VI:16 in the context of an aromatic residue at VII:09 and a large hydrophobic residue at VII:06. It is concluded that the three ghrelin-like receptors display an unusually high degree of constitutive activity, the structural basis for which is determined by an aromatic cluster on the inner face of the extracellular ends of TMs VI and VII.

Received for publication, July 8, 2004 , and in revised form, September 14, 2004.

^* This study was supported in part by grants from The Novo Nordisk Foundation and the Danish Medical Research Council (to B. H.), a 7TM Biotech Competence Center grant from the Danish Medical Research Council (to T. W. S.), and by the Kimmel Cancer Foundation (to H. M. C.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

To whom correspondence should be addressed. Tel.: 45-3532-7602; Fax: 45-3532-7610; E-mail: b.holst{at}molpharm.dk.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				B. Holst, K. L. Egerod, C. Jin, P. S. Petersen, M. V. Ostergaard, J. Hald, A. M. E. Sprinkel, J. Storling, T. Mandrup-Poulsen, J. J. Holst, et al. G Protein-Coupled Receptor 39 Deficiency Is Associated with Pancreatic Islet Dysfunction Endocrinology, June 1, 2009; 150(6): 2577 - 2585. [Abstract] [Full Text] [PDF]

				F. Tremblay, A.-M. T. Richard, S. Will, J. Syed, N. Stedman, M. Perreault, and R. E. Gimeno Disruption of G Protein-Coupled Receptor 39 Impairs Insulin Secretion in Vivo Endocrinology, June 1, 2009; 150(6): 2586 - 2595. [Abstract] [Full Text] [PDF]

				L. Besser, E. Chorin, I. Sekler, W. F. Silverman, S. Atkin, J. T. Russell, and M. Hershfinkel Synaptically Released Zinc Triggers Metabotropic Signaling via a Zinc-Sensing Receptor in the Hippocampus J. Neurosci., March 4, 2009; 29(9): 2890 - 2901. [Abstract] [Full Text] [PDF]

				B. Holst, T. M. Frimurer, J. Mokrosinski, T. Halkjaer, K. B. Cullberg, C. R. Underwood, and T. W. Schwartz Overlapping Binding Site for the Endogenous Agonist, Small-Molecule Agonists, and Ago-allosteric Modulators on the Ghrelin Receptor Mol. Pharmacol., January 1, 2009; 75(1): 44 - 59. [Abstract] [Full Text] [PDF]

				Y. Zhang, Y. Liu, X. Huang, X. Liu, B. Jiao, Z. Meng, P. Zhu, S. Li, H. Lin, and C. H K Cheng Two alternatively spliced GPR39 transcripts in seabream: molecular cloning, genomic organization, and regulation of gene expression by metabolic signals J. Endocrinol., December 1, 2008; 199(3): 457 - 470. [Abstract] [Full Text] [PDF]

				T. Benned-Jensen and M. M. Rosenkilde Structural Motifs of Importance for the Constitutive Activity of the Orphan 7TM Receptor EBI2: Analysis of Receptor Activation in the Absence of an Agonist Mol. Pharmacol., October 1, 2008; 74(4): 1008 - 1021. [Abstract] [Full Text] [PDF]

				S. Dittmer, M. Sahin, A. Pantlen, A. Saxena, D. Toutzaris, A.-L. Pina, A. Geerts, S. Golz, and A. Methner The Constitutively Active Orphan G-protein-coupled Receptor GPR39 Protects from Cell Death by Increasing Secretion of Pigment Epithelium-derived Growth Factor J. Biol. Chem., March 14, 2008; 283(11): 7074 - 7081. [Abstract] [Full Text] [PDF]

				N. D. Holliday, B. Holst, E. A. Rodionova, T. W. Schwartz, and H. M. Cox Importance of Constitutive Activity and Arrestin-Independent Mechanisms for Intracellular Trafficking of the Ghrelin Receptor Mol. Endocrinol., December 1, 2007; 21(12): 3100 - 3112. [Abstract] [Full Text] [PDF]

				G. Liu, J.-P. Fortin, M. Beinborn, and A. S. Kopin Four Missense Mutations in the Ghrelin Receptor Result in Distinct Pharmacological Abnormalities J. Pharmacol. Exp. Ther., September 1, 2007; 322(3): 1036 - 1043. [Abstract] [Full Text] [PDF]

				K. L. Egerod, B. Holst, P. S. Petersen, J. B. Hansen, J. Mulder, T. Hokfelt, and T. W. Schwartz GPR39 Splice Variants Versus Antisense Gene LYPD1: Expression and Regulation in Gastrointestinal Tract, Endocrine Pancreas, Liver, and White Adipose Tissue Mol. Endocrinol., July 1, 2007; 21(7): 1685 - 1698. [Abstract] [Full Text] [PDF]

				B. Holst, J. Mokrosinski, M. Lang, E. Brandt, R. Nygaard, T. M. Frimurer, A. G. Beck-Sickinger, and T. W. Schwartz Identification of an Efficacy Switch Region in the Ghrelin Receptor Responsible for Interchange between Agonism and Inverse Agonism J. Biol. Chem., May 25, 2007; 282(21): 15799 - 15811. [Abstract] [Full Text] [PDF]

				L. A. Stoddart, A. J. Brown, and G. Milligan Uncovering the Pharmacology of the G Protein-Coupled Receptor GPR40: High Apparent Constitutive Activity in Guanosine 5'-O-(3-[35S]thio)triphosphate Binding Studies Reflects Binding of an Endogenous Agonist Mol. Pharmacol., April 1, 2007; 71(4): 994 - 1005. [Abstract] [Full Text] [PDF]

				Q. Deng, J. A. Clemas, G. Chrebet, P. Fischer, J. J. Hale, Z. Li, S. G. Mills, J. Bergstrom, S. Mandala, R. Mosley, et al. Identification of Leu276 of the S1P1 Receptor and Phe263 of the S1P3 Receptor in Interaction with Receptor Specific Agonists by Molecular Modeling, Site-Directed Mutagenesis, and Affinity Studies Mol. Pharmacol., March 1, 2007; 71(3): 724 - 735. [Abstract] [Full Text] [PDF]

				M. M. Rosenkilde, M. B. Andersen, R. Nygaard, T. M. Frimurer, and T. W. Schwartz Activation of the CXCR3 Chemokine Receptor through Anchoring of a Small Molecule Chelator Ligand between TM-III, -IV, and -VI Mol. Pharmacol., March 1, 2007; 71(3): 930 - 941. [Abstract] [Full Text] [PDF]

				F. Tremblay, M. Perreault, L. D. Klaman, J. F. Tobin, E. Smith, and R. E. Gimeno Normal Food Intake and Body Weight in Mice Lacking the G Protein-Coupled Receptor GPR39 Endocrinology, February 1, 2007; 148(2): 501 - 506. [Abstract] [Full Text] [PDF]

				B. Holst, K. L. Egerod, E. Schild, S. P. Vickers, S. Cheetham, L.-O. Gerlach, L. Storjohann, C. E. Stidsen, R. Jones, A. G. Beck-Sickinger, et al. GPR39 Signaling Is Stimulated by Zinc Ions But Not by Obestatin Endocrinology, January 1, 2007; 148(1): 13 - 20. [Abstract] [Full Text] [PDF]

				S. Choi, M. Lee, A. L. Shiu, S. J. Yo, and G. W. Aponte Identification of a protein hydrolysate responsive G protein-coupled receptor in enterocytes Am J Physiol Gastrointest Liver Physiol, January 1, 2007; 292(1): G98 - G112. [Abstract] [Full Text] [PDF]

				X. Zhu, Y. Cao, K. Voodg, and D. F. Steiner On the Processing of Proghrelin to Ghrelin J. Biol. Chem., December 15, 2006; 281(50): 38867 - 38870. [Abstract] [Full Text] [PDF]

				K. Dezaki, H. Sone, M. Koizumi, M. Nakata, M. Kakei, H. Nagai, H. Hosoda, K. Kangawa, and T. Yada Blockade of Pancreatic Islet-Derived Ghrelin Enhances Insulin Secretion to Prevent High-Fat Diet-Induced Glucose Intolerance Diabetes, December 1, 2006; 55(12): 3486 - 3493. [Abstract] [Full Text] [PDF]

				M. C Carreira, J. P Camina, E. Diaz-Rodriguez, R. Alvear-Perez, C. Llorens-Cortes, and F. F Casanueva Adenosine does not bind to the growth hormone secretagogue receptor type-1a (GHS-R1a). J. Endocrinol., October 1, 2006; 191(1): 147 - 157. [Abstract] [Full Text] [PDF]

				B. Holst, M. Lang, E. Brandt, A. Bach, A. Howard, T. M. Frimurer, A. Beck-Sickinger, and T. W. Schwartz Ghrelin Receptor Inverse Agonists: Identification of an Active Peptide Core and Its Interaction Epitopes on the Receptor Mol. Pharmacol., September 1, 2006; 70(3): 936 - 946. [Abstract] [Full Text] [PDF]

				H D. Falls, B. D Dayton, D. G Fry, C. A Ogiela, V. G Schaefer, S. Brodjian, R. M Reilly, C. A Collins, and W. Kaszubska Characterization of ghrelin receptor activity in a rat pituitary cell line RC-4B/C. J. Mol. Endocrinol., August 1, 2006; 37(1): 51 - 62. [Abstract] [Full Text] [PDF]

				C. E. Elling, T. M. Frimurer, L.-O. Gerlach, R. Jorgensen, B. Holst, and T. W. Schwartz Metal Ion Site Engineering Indicates a Global Toggle Switch Model for Seven-transmembrane Receptor Activation J. Biol. Chem., June 23, 2006; 281(25): 17337 - 17346. [Abstract] [Full Text] [PDF]

				M. M. Rosenkilde, T. Benned-Jensen, H. Andersen, P. J. Holst, T. N. Kledal, H. R. Luttichau, J. K. Larsen, J. P. Christensen, and T. W. Schwartz Molecular Pharmacological Phenotyping of EBI2: AN ORPHAN SEVEN-TRANSMEMBRANE RECEPTOR WITH CONSTITUTIVE ACTIVITY J. Biol. Chem., May 12, 2006; 281(19): 13199 - 13208. [Abstract] [Full Text] [PDF]

				J. V. Zhang, P.-G. Ren, O. Avsian-Kretchmer, C.-W. Luo, R. Rauch, C. Klein, and A. J. W. Hsueh Obestatin, a Peptide Encoded by the Ghrelin Gene, Opposes Ghrelin's Effects on Food Intake Science, November 11, 2005; 310(5750): 996 - 999. [Abstract] [Full Text] [PDF]

				B. Holst, E. Brandt, A. Bach, A. Heding, and T. W. Schwartz Nonpeptide and Peptide Growth Hormone Secretagogues Act Both as Ghrelin Receptor Agonist and as Positive or Negative Allosteric Modulators of Ghrelin Signaling Mol. Endocrinol., September 1, 2005; 19(9): 2400 - 2411. [Abstract] [Full Text] [PDF]