Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Anomalous mole fraction effect induced by mutation of the H5 pore region in the Shaker K+ channel.
Yool AJ
,
Schwarz TL
.
???displayArticle.abstract???
Mutagenesis of the H5 region of the Shaker K+ channel has provided strong evidence that these amino acids form a major portion of the ionic pore. We have previously observed that a single-site mutation (T441S) in this region increased the apparent relative permeability of the channel to NH4+. We now report that this increased relative permeability to NH4+ is sensitive to small changes in external K+ in a pattern consistent with an anomalous mole fraction effect. The effect is not apparent in the wild-type channel. These findings, in combination with other studies showing effects of this particular mutation on the binding of tetraethylammonium and hydroxylamine, support the hypothesis that T441S alters the affinity of a putative ion binding site for NH4+ and ammonium derivatives. The mutation T441S alters ionic selectivity and reveals the multi-ion nature of the mutant Shaker K+ channel.
Almers,
Non-selective conductance in calcium channels of frog muscle: calcium selectivity in a single-file pore.
1984, Pubmed
Almers,
Non-selective conductance in calcium channels of frog muscle: calcium selectivity in a single-file pore.
1984,
Pubmed
Ashcroft,
The influence of the permeant ions thallous and potassium on inward rectification in frog skeletal muscle.
1983,
Pubmed
Begenisich,
Sodium channel permeation in squid axons. I: Reversal potential experiments.
1980,
Pubmed
Catterall,
Structure and function of voltage-gated ion channels.
1993,
Pubmed
Eisenman,
Multi-ion conduction and selectivity in the high-conductance Ca++-activated K+ channel from skeletal muscle.
1986,
Pubmed
Friel,
Voltage-gated calcium channels: direct observation of the anomalous mole fraction effect at the single-channel level.
1989,
Pubmed
Hagiwara,
Anomalous permeabilities of the egg cell membrane of a starfish in K+-Tl+ mixtures.
1977,
Pubmed
Heginbotham,
Conduction properties of the cloned Shaker K+ channel.
1993,
Pubmed
,
Xenbase
Heginbotham,
Mutations in the K+ channel signature sequence.
1994,
Pubmed
,
Xenbase
Hess,
Mechanism of ion permeation through calcium channels.
,
Pubmed
Hille,
Potassium channels as multi-ion single-file pores.
1978,
Pubmed
Kirsch,
A single nonpolar residue in the deep pore of related K+ channels acts as a K+:Rb+ conductance switch.
1992,
Pubmed
Lopez,
Evidence that the S6 segment of the Shaker voltage-gated K+ channel comprises part of the pore.
1994,
Pubmed
,
Xenbase
MacKinnon,
New insights into the structure and function of potassium channels.
1991,
Pubmed
Newland,
Repulsion between tetraethylammonium ions in cloned voltage-gated potassium channels.
1992,
Pubmed
,
Xenbase
Plant,
The effects of rubidium ions on components of the potassium conductance in the frog node of Ranvier.
1986,
Pubmed
Pérez-Cornejo,
The multi-ion nature of the pore in Shaker K+ channels.
1994,
Pubmed
Sather,
Structural basis of ion channel permeation and selectivity.
1994,
Pubmed
Shapiro,
Selectivity and gating of the type L potassium channel in mouse lymphocytes.
1991,
Pubmed
Slesinger,
The S4-S5 loop contributes to the ion-selective pore of potassium channels.
1993,
Pubmed
,
Xenbase
Tabcharani,
Multi-ion pore behaviour in the CFTR chloride channel.
1993,
Pubmed
Taglialatela,
Comparison of H5, S6, and H5-S6 exchanges on pore properties of voltage-dependent K+ channels.
1994,
Pubmed
,
Xenbase
Wagoner,
Cation permeation through the voltage-dependent potassium channel in the squid axon. Characteristics and mechanisms.
1987,
Pubmed
Yellen,
Mutations affecting internal TEA blockade identify the probable pore-forming region of a K+ channel.
1991,
Pubmed
Yool,
Alteration of ionic selectivity of a K+ channel by mutation of the H5 region.
1991,
Pubmed
,
Xenbase
Yool,
Block of the inactivating potassium channel by clofilium and hydroxylamine depends on the sequence of the pore region.
1994,
Pubmed
,
Xenbase
Yool,
Interactions of the H5 pore region and hydroxylamine with N-type inactivation in the Shaker K+ channel.
1995,
Pubmed
,
Xenbase