A Functional Connection Between the Pores of Distantly Related Ion Channels as Revealed by Mutant K + Channels
- 13 November 1992
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 258 (5085), 1152-1155
- https://doi.org/10.1126/science.1279807
Abstract
The overall sequence similarity between the voltage-activated K+ channels and cyclic nucleotide-gated ion channels from retinal and olfactory neurons suggests that they arose from a common ancestor. On the basis of sequence comparisons, mutations were introduced into the pore of a voltage-activated K+ channel. These mutations confer the essential features of ion conduction in the cyclic nucleotide-gated ion channels; the mutant K+ channels display little selectivity among monovalent cations and are blocked by divalent cations. The property of K+ selectivity is related to the presence of two amino acids that are absent from the pore-forming region of the cyclic nucleotide-gated channels. These data demonstrate that very small differences in the primary structure of an ion channel can account for extreme functional diversity, and they suggest a possible connection between the pore-forming regions of K+, Ca2+, and cyclic nucleotide-gated ion channels.Keywords
This publication has 36 references indexed in Scilit:
- Calcium-activated potassium channels expressed from cloned complementary DNAsNeuron, 1992
- Calcium channel characteristics conferred on the sodium channel by single mutationsNature, 1992
- Molecular cloning and single-channel properties of the cyclic nucleotide-gated channel from catfish olfactory neuronsNeuron, 1992
- Voltage-sensing residues in the S4 region of a mammalian K+ channelNature, 1991
- A Component of Calcium-activated Potassium Channels Encoded by the Drosophila slo LocusScience, 1991
- Alteration of ionic selectivity of a K+ channel by mutation of the H5 regionNature, 1991
- Mapping the receptor site for charybdotoxin, a pore-blocking potassium channel inhibitorNeuron, 1990
- Mutations Affecting Tea Blockade and Ion Permeation in Voltage-activated K + ChannelsScience, 1990
- Cyclic GMP-sensitive conductance of retinal rods consists of aqueous poresNature, 1986
- Single cyclic GMP-activated channel activity in excised patches of rod outer segment membraneNature, 1986