QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: mol.105.011239v1 68/1/11    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Rosenkilde, M. M. Articles by Schwartz, T. W. Search for Related Content PubMed PubMed Citation Articles by Rosenkilde, M. M. Articles by Schwartz, T. W.

High Constitutive Activity of a Virus-Encoded Seven Transmembrane Receptor in the Absence of the Conserved DRY Motif (Asp-Arg-Tyr) in Transmembrane Helix 3

Laboratory for Molecular Pharmacology, Department of Pharmacology, The Panum Institute, University of Copenhagen, Copenhagen N, Denmark (M.M.R., T.W.S.); and Clinical Research Unit, Hvidovre Hospital, Hvidovre, Denmark (T.N.K.)

The highly conserved Arg in the so-called DRY motif (Asp-Arg-Tyr) at the intracellular end of transmembrane helix 3 is in general considered as an essential residue for G protein coupling in rhodopsin-like seven transmembrane (7TM) receptors. In the open reading frame 74 (ORF74) receptor encoded by equine herpesvirus 2 (EHV2), the DRY motif is substituted with a DTW motif. Nevertheless, this receptor signaled with high constitutive activity through Gi as determined by a receptor-mediated inhibition of forskolin-induced cAMP-production and by an induction of the serum response element-driven transcriptional activity through a pertussis toxin-sensitive manner. Gs and Gq were not activated constitutively as determined by the lack of inositol phosphate turnover and activities of the three transcription factors: cAMP response element-binding protein (CREB), nuclear factor-B, and nuclear factor of activated T cells. Coexpression of the ORF74-EHV2 receptor with the promiscuous G protein Gqi4myr supported the constitutive Gi activation as determined by inositol phosphate turnover and CREB activation. The constitutive activity was inhibited by nonpeptide inverse agonists with micromolar potencies, and the chemokine CXCL6 acted as a high-affinity agonist. It is noteworthy that reconstitution of the DRY motif resulted in a 4- to 5-fold decrease of the constitutive activity. Both the wild type and the receptor with the reconstituted DRY motif were expressed at the cell surface as indicated by immunohistochemistry and enzyme-linked immunosorbent assay analysis. It is concluded that the Arg of the DRY motif in transmembrane helix 3 is not essential for G protein coupling based on the constitutive as well as the ligand-mediated activity observed for ORF74-EHV2.

Address correspondence to: Dr. Mette M. Rosenkilde, Laboratory for Molecular Pharmacology, Department of Pharmacology, The Panum Institute 18.6, Blegdamsvej 3, 2200 Copenhagen N, Denmark. E-mail: rosenkilde{at}molpharm.dk

This article has been cited by other articles:

				R. Case, E. Sharp, T. Benned-Jensen, M. M. Rosenkilde, N. Davis-Poynter, and H. E. Farrell Functional Analysis of the Murine Cytomegalovirus Chemokine Receptor Homologue M33: Ablation of Constitutive Signaling Is Associated with an Attenuated Phenotype In Vivo J. Virol., February 15, 2008; 82(4): 1884 - 1898. [Abstract] [Full Text] [PDF]

				E. L. Sharp, H. E. Farrell, K. Borchers, E. C. Holmes, and N. J. Davis-Poynter Sequence analysis of the equid herpesvirus 2 chemokine receptor homologues E1, ORF74 and E6 demonstrates high sequence divergence between field isolates J. Gen. Virol., September 1, 2007; 88(9): 2450 - 2462. [Abstract] [Full Text] [PDF]

				V. Binet, B. Duthey, J. Lecaillon, C. Vol, J. Quoyer, G. Labesse, J.-P. Pin, and L. Prezeau Common Structural Requirements for Heptahelical Domain Function in Class A and Class C G Protein-coupled Receptors J. Biol. Chem., April 20, 2007; 282(16): 12154 - 12163. [Abstract] [Full Text] [PDF]

				J. D. Sherrill and W. E. Miller G Protein-coupled Receptor (GPCR) Kinase 2 Regulates Agonist-independent Gq/11 Signaling from the Mouse Cytomegalovirus GPCR M33 J. Biol. Chem., December 29, 2006; 281(52): 39796 - 39805. [Abstract] [Full Text] [PDF]

				M. M. Rosenkilde, R. David, I. Oerlecke, T. Benned-Jensen, U. Geumann, A. G. Beck-Sickinger, and T. W. Schwartz Conformational Constraining of Inactive and Active States of a Seven Transmembrane Receptor by Metal Ion Site Engineering in the Extracellular End of Transmembrane Segment V Mol. Pharmacol., December 1, 2006; 70(6): 1892 - 1901. [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]

				P. Najarro, C. Gubser, M. Hollinshead, J. Fox, J. Pease, and G. L. Smith Yaba-like disease virus chemokine receptor 7L, a CCR8 orthologue. J. Gen. Virol., April 1, 2006; 87(Pt 4): 809 - 816. [Abstract] [Full Text] [PDF]

				C. P. Fitzsimons, U. A. Gompels, D. Verzijl, H. F. Vischer, C. Mattick, R. Leurs, and M. J. Smit Chemokine-Directed Trafficking of Receptor Stimulus to Different G Proteins: Selective Inducible and Constitutive Signaling by Human Herpesvirus 6-Encoded Chemokine Receptor U51 Mol. Pharmacol., March 1, 2006; 69(3): 888 - 898. [Abstract] [Full Text] [PDF]

				C. A. Flanagan A GPCR That Is Not "DRY" Mol. Pharmacol., July 1, 2005; 68(1): 1 - 3. [Abstract] [Full Text] [PDF]