Characterizing ligand-gated ion channel receptors with genetically encoded Ca2++ sensors

PLoS One. 2011 Jan 28;6(1):e16519. doi: 10.1371/journal.pone.0016519.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biosensing Techniques / methods*
  • Calcium / analysis*
  • Cell Line
  • Dose-Response Relationship, Drug
  • Fluorescence Resonance Energy Transfer
  • Humans
  • Ion Channel Gating
  • Ligand-Gated Ion Channels / metabolism*
  • Ligands
  • Mice
  • Receptors, Nicotinic / metabolism
  • Receptors, Serotonin / metabolism


  • Ligand-Gated Ion Channels
  • Ligands
  • Receptors, Nicotinic
  • Receptors, Serotonin
  • Calcium