Characterization of KCNQ5/Q3 potassium channels expressed in mammalian cells

Br J Pharmacol. 2001 Jan;132(2):381-4. doi: 10.1038/sj.bjp.0703861.


Heteromeric KCNQ5/Q3 channels were stably expressed in Chinese Hamster ovary cells and characterized using the whole cell voltage-clamp technique. KCNQ5/Q3 channels were activated by the novel anticonvulsant, retigabine (EC(50) 1.4 microM) by a mechanism that involved drug-induced, leftward shifts in the voltage-dependence of channel activation (-31.8 mV by 30 microM retigabine). KCNQ5/Q3 channels were inhibited by linopirdine (IC(50) 7.7 microM) and barium (IC(50) 0.46 mM), at concentrations similar to those required to inhibit native M-currents. These findings identify KCNQ5/Q3 channels as a molecular target for retigabine and raise the possibility that activation of KCNQ5/Q3 channels may be responsible for some of the anti-convulsant activity of this agent. Furthermore, the sensitivity of KCNQ5/Q3 channels to linopirdine supports the possibility that potassium channels comprised of KCNQ5 and KCNQ3 may make a contribution to native M-currents.

MeSH terms

  • Animals
  • Anticonvulsants / pharmacology
  • Barium / pharmacology
  • CHO Cells
  • Carbamates / pharmacology
  • Cricetinae
  • Electrophysiology
  • Indoles / pharmacology
  • KCNQ3 Potassium Channel
  • Oocytes / drug effects
  • Oocytes / metabolism
  • Patch-Clamp Techniques
  • Phenylenediamines / pharmacology
  • Plasmids
  • Potassium Channels / agonists
  • Potassium Channels / genetics
  • Potassium Channels / physiology*
  • Potassium Channels, Voltage-Gated*
  • Pyridines / pharmacology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Xenopus laevis


  • Anticonvulsants
  • Carbamates
  • Indoles
  • KCNQ3 Potassium Channel
  • Phenylenediamines
  • Potassium Channels
  • Potassium Channels, Voltage-Gated
  • Pyridines
  • ezogabine
  • Barium
  • linopirdine