Role of membrane cholesterol in differential sensitivity of muscarinic receptor subtypes to persistently bound xanomeline
| Autor: | Pavel Zimčík, Eva Dolejší, Vladimír Rudajev, Vladimír Doležal, Jan Jakubík, Alena Randáková, Esam E. El-Fakahany |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Models Molecular Magnetic Resonance Spectroscopy Pyridines Inositol Phosphates CHO Cells Muscarinic Agonists Tritium Muscarinic agonist 03 medical and health sciences Cellular and Molecular Neuroscience chemistry.chemical_compound Radioligand Assay Cricetulus Muscarinic acetylcholine receptor Thiadiazoles Functional selectivity Animals Binding site Receptor G protein-coupled receptor Pharmacology Cholesterol binding Cell Membrane Flow Cytometry Receptors Muscarinic Cell biology Molecular Docking Simulation 030104 developmental biology Cholesterol chemistry Calcium Xanomeline |
| Zdroj: | Neuropharmacology. 133 |
| ISSN: | 1873-7064 |
| Popis: | Xanomeline (3-(Hexyloxy)-4-(1-methyl-1,2,5,6-tetrahydropyridin-3-yl)-1,2,5-thiadiazole) is a muscarinic agonist that is considered to be functionally selective for the M1/M4 receptor subtypes. Part of xanomeline binding is resistant to washing. Wash-resistant xanomeline activates muscarinic receptors persistently, except for the M5 subtype. Mutation of leucine 6.46 to isoleucine at M1 or M4 receptors abolished persistent activation by wash-resistant xanomeline. Reciprocal mutation of isoleucine 6.46 to leucine at the M5 receptor made it sensitive to activation by wash-resistant xanomeline. Lowering of membrane cholesterol made M1 and M4 mutants and M5 wild type receptors sensitive to activation by wash-resistant xanomeline. Molecular docking revealed a cholesterol binding site in the groove between transmembrane helices 6 and 7. Molecular dynamics showed that interaction of cholesterol with this binding site attenuates receptor activation. We hypothesize that differences in cholesterol binding to this site between muscarinic receptor subtypes may constitute the basis for xanomeline apparent functional selectivity and may have notable therapeutic implications. Differences in receptor-membrane interactions, rather than in agonist-receptor interactions, represent a novel possibility to achieve pharmacological selectivity. Our findings may be applicable to other G protein coupled receptors. |
| Databáze: | OpenAIRE |
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