Determination of the subunit stoichiometry of a voltage-activated potassium channel
Abstract
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 subunits1-3. 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+ channels4-6.
- Publication:
-
Nature
- Pub Date:
- March 1991
- DOI:
- 10.1038/350232a0
- Bibcode:
- 1991Natur.350..232M