title: Detection and quantification of allosteric modulation of endogenous m4 muscarinic acetylcholine receptor using impedance-based label-free technology in a neuronal cell line.
abstract: Allosteric modulators of G protein-coupled receptors have the potential to achieve greater receptor subtype selectivity compared with ligands targeting the orthosteric site of this receptor family. However, the high attrition rate in GPCR drug discovery programs has highlighted the need to better characterize lead compounds in terms of their allosteric action, as well as the signals they elicit. Recently, the use of label-free technologies has been proposed as an approach to overcome some limitations of endpoint-based assays and detect global changes in the ligand-stimulated cell. In this study, we assessed the ability of an impedance-based label-free technology, xCELLigence, to detect allosteric modulation in a neuronal cell line natively expressing rodent M4 muscarinic acetylcholine receptors. We were able to demonstrate that positive allosteric modulation of the endogenous M4 muscarinic acetylcholine receptor can be detected using this technology. Importantly, the allosteric parameters estimated from the label-free approach are comparable to those estimated from endpoint-based assays.
authors.affiliation: Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
authors.forename: Amy N Y
authors.initials: AN
authors.lastname: Chen
authors.affiliation: Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Malone
authors.affiliation: Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
authors.forename: Kavita
authors.initials: K
authors.lastname: Pabreja
authors.affiliation: Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Sexton
authors.affiliation: Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
authors.forename: Arthur
authors.initials: A
authors.lastname: Christopoulos
authors.affiliation: Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia meri.canals@monash.edu.
authors.forename: Meritxell
authors.initials: M
authors.lastname: Canals
mesh_terms: D000494:Allosteric Regulation; D015374:Biosensing Techniques; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery / Q000379:methods*; D017097:Electric Impedance; D015870:Gene Expression; D006801:Humans; D008024:Ligands; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding; D043588:Receptor, Muscarinic M4 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D008024:Ligands; D043588:Receptor, Muscarinic M4
keywords: G protein–coupled receptor; cell impedance; label-free technology; muscarinic acetylcholine receptor; positive allosteric modulator