Constitutive Activation of the ␦ Opioid Receptor by Mutations in Transmembrane Domains III and VII
| Autor: | ShiYi Yue, Dominique Filliol, Katia Befort, Christelle Zilliox, Brigitte L. Kieffer |
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| Přispěvatelé: | Laboratoire des Récepteurs et Protéines Membranaires (UPR CNRS 9050), Ecole Supérieure de Biotechnologie de Strasbourg (ESBS), Université de Strasbourg (UNISTRA)-Université de Strasbourg (UNISTRA) |
| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: |
Models
Molecular medicine.drug_class Narcotic Antagonists Biology Ligands 01 natural sciences Biochemistry Protein Structure Secondary Mice Structure-Activity Relationship 03 medical and health sciences 0302 clinical medicine Opioid receptor Receptors Opioid delta medicine Enzyme-linked receptor Animals 5-HT5A receptor GABBR2 GABBR1 Receptor Molecular Biology Insulin-like growth factor 1 receptor 030304 developmental biology 0303 health sciences [CHIM.ORGA]Chemical Sciences/Organic chemistry Cell Membrane Cell Biology Ligand (biochemistry) Enkephalin Leucine-2-Alanine Molecular biology Naltrexone 0104 chemical sciences 010404 medicinal & biomolecular chemistry Amino Acid Substitution Guanosine 5'-O-(3-Thiotriphosphate) COS Cells Biophysics Mutagenesis Site-Directed 030217 neurology & neurosurgery |
| Zdroj: | Journal of Biological Chemistry Journal of Biological Chemistry, American Society for Biochemistry and Molecular Biology, 1999, 274 (26), pp.18574-18581. ⟨10.1074/jbc.274.26.18574⟩ |
| ISSN: | 0021-9258 1083-351X |
| Popis: | We have investigated whether transmembrane amino acid residues Asp128 (domain III), Tyr129 (domain III) [corrected], and Tyr308 (domain VII) in the mouse delta opioid receptor play a role in receptor activation. To do so, we have used a [35S]GTPgammaS (where GTPgammaS is guanosine 5'-3-O-(thio)triphosphate) binding assay to quantify the activation of recombinant receptors transiently expressed in COS cells and compared functional responses of D128N, D128A, Y129F, Y129A, and Y308F point-mutated receptors to that of the wild-type receptor. In the absence of ligand, [35S]GTPgammaS binding was increased for every mutant receptor under study (1.6-2.6-fold), suggesting that all mutations are able to enhance constitutive activity at the receptor. In support of this finding, the inverse agonist N,N-diallyl-Tyr-Aib-Aib-Phe-Leu (where Aib represents alpha-aminobutyric acid) efficiently reduced basal [35S]GTPgammaS binding in the mutated receptor preparations. The potent agonist BW373U86 stimulated [35S]GTPgammaS binding above basal levels with similar (D128N, Y129F, and Y129A) or markedly increased (Y308F) efficacy compared with wild-type receptor. BW373U86 potency was maintained or increased. In conclusion, our results demonstrate that the mutations under study increase functional activity of the receptor. Three-dimensional modeling suggests that Asp128 (III) and Tyr308 (VII) interact with each other and that Tyr129 (III) undergoes H bonding with His278 (VI). Thus, Asp128, Tyr129, and Tyr308 may be involved in a network of interhelical bonds, which contributes to maintain the delta receptor under an inactive conformation. We suggest that the mutations weaken helix-helix interactions and generate a receptor state that favors the active conformation and/or interacts with heterotrimeric G proteins more effectively. |
| Databáze: | OpenAIRE |
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