Determination of the subunit stoichiometry of a voltage-activated potassium channel

Nature. 1991 Mar 21;350(6315):232-5. doi: 10.1038/350232a0.


The voltage-activated K+, Na+ and Ca2+ channels are responsible for the generation and propagation of electrical signals in cell membranes. The K+ channels are multimeric membrane proteins formed by the aggregation of an unknown number of independent subunits. By studying the interaction of a scorpion toxin with coexpressed wild-type and toxin-insensitive mutant Shaker K+ channels, the subunit stoichiometry can be determined. The Shaker K+ channel is found to have a tetrameric structure. This is consistent with the sequence relationship between a K+ channel and each of the four internally homologous repeats of Na+ and Ca2+ channels.

Publication types

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

MeSH terms

  • Animals
  • Charybdotoxin
  • Membrane Potentials
  • Membrane Proteins / physiology
  • Mutation
  • Potassium Channels / drug effects
  • Potassium Channels / genetics
  • Potassium Channels / physiology*
  • RNA / metabolism
  • Scorpion Venoms / toxicity
  • Xenopus


  • Membrane Proteins
  • Potassium Channels
  • Scorpion Venoms
  • Charybdotoxin
  • RNA