Copper-mediated thiol potentiation and mutagenesis-guided modeling suggest a highly conserved copper-binding motif in human OR2M3
| Autor: | Lucky Ahmed, Krystle Reiss, Victor S. Batista, Franziska Haag, Dietmar Krautwurst, Eric Block |
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| Rok vydání: | 2019 |
| Předmět: |
Models
Molecular Molecular model Amino Acid Motifs Molecular modeling chemistry.chemical_element Receptors Odorant law.invention 03 medical and health sciences Cellular and Molecular Neuroscience GPCR law Metalloprotein Humans Amino Acid Sequence Sulfhydryl Compounds Homology modeling Receptor Molecular Biology Conserved Sequence Phylogeny G protein-coupled receptor Pharmacology chemistry.chemical_classification 0303 health sciences Silver ions Binding Sites 030302 biochemistry & molecular biology Structure–function study Cell Biology Copper ddc Copper-binding motif HEK293 Cells Biochemistry chemistry Docking (molecular) Mutagenesis Site-Directed Recombinant DNA Molecular Medicine Original Article |
| Zdroj: | Cellular and Molecular Life Sciences |
| ISSN: | 1420-9071 1420-682X |
| DOI: | 10.1007/s00018-019-03279-y |
| Popis: | Sulfur-containing compounds within a physiological relevant, natural odor space, such as the key food odorants, typically constitute the group of volatiles with the lowest odor thresholds. The observation that certain metals, such as copper, potentiate the smell of sulfur-containing, metal-coordinating odorants led to the hypothesis that their cognate receptors are metalloproteins. However, experimental evidence is sparse—so far, only one human odorant receptor, OR2T11, and a few mouse receptors, have been reported to be activated by sulfur-containing odorants in a copper-dependent way, while the activation of other receptors by sulfur-containing odorants did not depend on the presence of metals. Here we identified an evolutionary conserved putative copper interaction motif CC/CSSH, comprising two copper-binding sites in TMH5 and TMH6, together with the binding pocket for 3-mercapto-2-methylpentan-1-ol in the narrowly tuned human receptor OR2M3. To characterize the copper-binding motif, we combined homology modeling, docking studies, site-directed mutagenesis, and functional expression of recombinant ORs in a cell-based, real-time luminescence assay. Ligand activation of OR2M3 was potentiated in the presence of copper. This effect of copper was mimicked by ionic and colloidal silver. In two broadly tuned receptors, OR1A1 and OR2W1, which did not reveal a putative copper interaction motif, activation by their most potent, sulfur-containing key food odorants did not depend on the presence of copper. Our results suggest a highly conserved putative copper-binding motif to be necessary for a copper-modulated and thiol-specific function of members from three subfamilies of family 2 ORs. Electronic supplementary material The online version of this article (10.1007/s00018-019-03279-y) contains supplementary material, which is available to authorized users. |
| Databáze: | OpenAIRE |
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