Functional Stoichiometry of Shaker Potassium Channel Inactivation
- 29 October 1993
- journal article
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 262 (5134), 757-759
- https://doi.org/10.1126/science.7694359
Abstract
Shaker potassium channels from Drosophila are composed of four identical subunits. The contribution of a single subunit to the inactivation gating transition was investigated. Channels carrying a specific mutation in a single subunit can be labeled in a heterogeneous population and studied quantitatively with scorpion toxin sensitivity as a selection tag. Linkage within a single subunit of a mutation that removes the inactivation gate to a second mutation that affects scorpion toxin sensitivity demonstrates that only a single gate is necessary to produce inactivation. The inactivation rate constant for channels with a single gate was one-fourth that of channels with four gates. In contrast, the rate of recovery from inactivation was independent of the number of gates. It appears that each of the four open inactivation gates in a Shaker potassium channel is independent, but only one of the four gates closes in a mutually exclusive manner.Keywords
This publication has 8 references indexed in Scilit:
- Specification of Subunit Assembly by the Hydrophilic Amino-Terminal Domain of the Shaker Potassium ChannelScience, 1992
- Determination of the subunit stoichiometry of a voltage-activated potassium channelNature, 1991
- Mutations Affecting Internal TEA Blockade Identify the Probable Pore-Forming Region of a K + ChannelScience, 1991
- Restoration of Inactivation in Mutants of Shaker Potassium Channels by a Peptide Derived from ShBScience, 1990
- Biophysical and Molecular Mechanisms of Shaker Potassium Channel InactivationScience, 1990
- Charybdotoxin block of Shaker K+ channels suggests that different types of K+ channels share common structural featuresNeuron, 1988
- Destruction of Sodium Conductance Inactivation in Squid Axons Perfused with PronaseThe Journal of general physiology, 1973
- A quantitative description of membrane current and its application to conduction and excitation in nerveThe Journal of Physiology, 1952