Functional analysis of an archaebacterial voltage-dependent K+ channel

Nature. 2003 Mar 13;422(6928):180-5. doi: 10.1038/nature01473. Epub 2003 Mar 2.


All living organisms use ion channels to regulate the transport of ions across cellular membranes. Certain ion channels are classed as voltage-dependent because they have a voltage-sensing structure that induces their pores to open in response to changes in the cell membrane voltage. Until recently, the voltage-dependent K+, Ca2+ and Na+ channels were regarded as a unique development of eukaryotic cells, adapted to accomplish specialized electrical signalling, as exemplified in neurons. Here we present the functional characterization of a voltage-dependent K+ (K(V)) channel from a hyperthermophilic archaebacterium from an oceanic thermal vent. This channel possesses all the functional attributes of classical neuronal K(V) channels. The conservation of function reflects structural conservation in the voltage sensor as revealed by specific, high-affinity interactions with tarantula venom toxins, which evolved to inhibit eukaryotic K(V) channels.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Archaea* / genetics
  • Cloning, Molecular
  • Electric Conductivity
  • Escherichia coli
  • Eukaryotic Cells
  • Evolution, Molecular
  • Ion Channel Gating / drug effects
  • Japan
  • Membrane Potentials / drug effects
  • Molecular Sequence Data
  • Pacific Ocean
  • Potassium Channels, Voltage-Gated / antagonists & inhibitors
  • Potassium Channels, Voltage-Gated / chemistry
  • Potassium Channels, Voltage-Gated / genetics
  • Potassium Channels, Voltage-Gated / metabolism*
  • Spider Venoms / pharmacology
  • Toxins, Biological / pharmacology


  • Potassium Channels, Voltage-Gated
  • Spider Venoms
  • Toxins, Biological