1. Characterizing ligand-gated ion channel receptors with genetically encoded Ca2++ sensors.
- Author
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Yamauchi JG, Nemecz Á, Nguyen QT, Muller A, Schroeder LF, Talley TT, Lindstrom J, Kleinfeld D, and Taylor P
- Subjects
- Animals, Cell Line, Dose-Response Relationship, Drug, Fluorescence Resonance Energy Transfer, Humans, Ion Channel Gating, Ligands, Mice, Receptors, Nicotinic metabolism, Receptors, Serotonin metabolism, Biosensing Techniques methods, Calcium analysis, Ligand-Gated Ion Channels metabolism
- Abstract
We present a cell based system and experimental approach to characterize agonist and antagonist selectivity for ligand-gated ion channels (LGIC) by developing sensor cells stably expressing a Ca(2+) permeable LGIC and a genetically encoded Förster (or fluorescence) resonance energy transfer (FRET)-based calcium sensor. In particular, we describe separate lines with human α7 and human α4β2 nicotinic acetylcholine receptors, mouse 5-HT(3A) serotonin receptors and a chimera of human α7/mouse 5-HT(3A) receptors. Complete concentration-response curves for agonists and Schild plots of antagonists were generated from these sensors and the results validate known pharmacology of the receptors tested. Concentration-response relations can be generated from either the initial rate or maximal amplitudes of FRET-signal. Although assaying at a medium throughput level, this pharmacological fluorescence detection technique employs a clonal line for stability and has versatility for screening laboratory generated congeners as agonists or antagonists on multiple subtypes of ligand-gated ion channels. The clonal sensor lines are also compatible with in vivo usage to measure indirectly receptor activation by endogenous neurotransmitters.
- Published
- 2011
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