Inactivation of KAT1 channel of guard cells at sub-millimolar concentrations of external potassium

Ferenc Horváth, Brigitte Hertel, Barnabás Wodala, Anna Moroni, Anette Hurst, Gerhard Thiel

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In the present study we investigated the effect of depleting K+o on the activity of a plant K+ channel, the inward rectifier KAT1 from Arabidopsis thaliana. Most voltage sensitive K+ channels are able to sense the concentration of extracellular K+ (K+o) and inactivate if K+o decreases to sublillimolar values. The channel was expressed in mammalian HEK293 cells and measured with patch clamp in the whole cell configuration. The effect of K+o depletion on channel activity was monitored from the tail currents before during and after washing K+ o from the medium. The data show that a depletion of K+o results in a decrease in channel conductance. This high sensitivity of the channel to K+o could serve as a safety mechanism, which inactivates the channel at low K+o and prevents in this way leakage of K+ from the cells via this type of channel.

Original languageEnglish
Pages (from-to)3-5
Number of pages3
JournalActa Biologica Szegediensis
Issue number1-2
Publication statusPublished - Dec 1 2005



  • Cation sensitive gating
  • HEK293
  • KAT1
  • Potassium affinity

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

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