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Rescue of lethal subunits into functional K+ channels.
Taglialatela M, Payne JP, Drewe JA, Brown AM.
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In a chimeric, voltage-dependent K+ channel (CHM), the valine at position 369 and the leucine at position 374 interact within the pore or P-region to regulate ion permeation and block. Here we show that the point mutation, CHM V369L, abolished channel function whereas previous experiments showed that CHM V369 and CHM V369I are functional. Coinjection of "lethal" CHM V369L cRNA with CHM L374V cRNA but not CHM cRNA generated functional heteromultimers. The whole-cell Rb+/K+ conductance ratio was 2.98 +/- 0.43 for CHM L374V and was reduced to 0.87 +/- 0.04 for the coexpressed CHM V369L and CHM L374V subunits. When single-channel currents were recorded, a single class of CHM V369L/CHM L374V heteromultimers was identified. This class was readily distinguishable from CHM L374V homomultimers by K+ conductance, gating, and blockade by internal tetraethylammonium. Coinjection experiments at various RNA ratios suggest that the CHM V369L/CHM L374V heteromultime, assuming it to be a tetramer, was composed of three CHM L374V subunits and one CHM V369L subunit. It appears that in the critical P-region of CHM position 369 may tolerate only one leucine.
Armstrong,
Interaction of tetraethylammonium ion derivatives with the potassium channels of giant axons.
1971, Pubmed
Armstrong,
Interaction of tetraethylammonium ion derivatives with the potassium channels of giant axons.
1971,
Pubmed Christie,
Heteropolymeric potassium channels expressed in Xenopus oocytes from cloned subunits.
1990,
Pubmed
,
Xenbase De Biasi,
Inactivation determined by a single site in K+ pores.
1993,
Pubmed Frech,
A novel potassium channel with delayed rectifier properties isolated from rat brain by expression cloning.
1989,
Pubmed
,
Xenbase Goldstein,
Cooperative polymerization reactions. Analytical approximations, numerical examples, and experimental strategy.
1986,
Pubmed Hartmann,
Exchange of conduction pathways between two related K+ channels.
1991,
Pubmed
,
Xenbase Isacoff,
Evidence for the formation of heteromultimeric potassium channels in Xenopus oocytes.
1990,
Pubmed
,
Xenbase Joho,
Toxin and kinetic profile of rat brain type III sodium channels expressed in Xenopus oocytes.
1990,
Pubmed
,
Xenbase Kavanaugh,
Multiple subunits of a voltage-dependent potassium channel contribute to the binding site for tetraethylammonium.
1992,
Pubmed
,
Xenbase Kirsch,
Differences between the deep pores of K+ channels determined by an interacting pair of nonpolar amino acids.
1992,
Pubmed
,
Xenbase Kirsch,
A single nonpolar residue in the deep pore of related K+ channels acts as a K+:Rb+ conductance switch.
1992,
Pubmed Kirsch,
Internal and external TEA block in single cloned K+ channels.
1991,
Pubmed
,
Xenbase Li,
Specification of subunit assembly by the hydrophilic amino-terminal domain of the Shaker potassium channel.
1992,
Pubmed MacKinnon,
Determination of the subunit stoichiometry of a voltage-activated potassium channel.
1991,
Pubmed
,
Xenbase McCormack,
A role for hydrophobic residues in the voltage-dependent gating of Shaker K+ channels.
1991,
Pubmed
,
Xenbase Noda,
Primary structure of Electrophorus electricus sodium channel deduced from cDNA sequence.
,
Pubmed Perozo,
Gating currents from a nonconducting mutant reveal open-closed conformations in Shaker K+ channels.
1993,
Pubmed Po,
Heteromultimeric assembly of human potassium channels. Molecular basis of a transient outward current?
1993,
Pubmed
,
Xenbase Richards,
Areas, volumes, packing and protein structure.
1977,
Pubmed Ruppersberg,
Heteromultimeric channels formed by rat brain potassium-channel proteins.
1990,
Pubmed
,
Xenbase Sala,
Voltage-dependent slowing of K channel closing kinetics by Rb+.
1991,
Pubmed Salkoff,
An essential 'set' of K+ channels conserved in flies, mice and humans.
1992,
Pubmed
,
Xenbase Schwarz,
Multiple potassium-channel components are produced by alternative splicing at the Shaker locus in Drosophila.
1988,
Pubmed Shapiro,
Permeant ion effects on the gating kinetics of the type L potassium channel in mouse lymphocytes.
1991,
Pubmed Shen,
Deletion analysis of K+ channel assembly.
1993,
Pubmed
,
Xenbase Taglialatela,
Patterns of internal and external tetraethylammonium block in four homologous K+ channels.
1991,
Pubmed
,
Xenbase Taglialatela,
Regulation of K+/Rb+ selectivity and internal TEA blockade by mutations at a single site in K+ pores.
1993,
Pubmed Tanabe,
Primary structure of the receptor for calcium channel blockers from skeletal muscle.
,
Pubmed VanDongen,
Alteration and restoration of K+ channel function by deletions at the N- and C-termini.
1990,
Pubmed Yellen,
Mutations affecting internal TEA blockade identify the probable pore-forming region of a K+ channel.
1991,
Pubmed Yokoyama,
Potassium channels from NG108-15 neuroblastoma-glioma hybrid cells. Primary structure and functional expression from cDNAs.
1989,
Pubmed
,
Xenbase Yool,
Alteration of ionic selectivity of a K+ channel by mutation of the H5 region.
1991,
Pubmed
,
Xenbase
