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The pore of plant K(+) channels is involved in voltage and pH sensing: domain-swapping between different K(+) channel alpha-subunits.
Hoth S
,
Geiger D
,
Becker D
,
Hedrich R
.
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Plant K(+) uptake channel types differ with respect to their voltage, Ca(2)+, and pH dependence. Here, we constructed recombinant chimeric channels between KST1, a member of the inward-rectifying, acid-activated KAT1 family, and AKT3, a member of the weakly voltage-dependent, proton-blocked AKT2/3 family. The homologous pore regions of AKT3 (amino acids 216 to 287) and KST1 (amino acids 217 to 289) have been exchanged to generate the two chimeric channels AKT3/(p)KST1 and KST1/(p)AKT3. In contrast to AKT3 wild-type channels, AKT3/(p)KST1 revealed a strong inward rectification reminiscent of that of KST1. Correspondingly, the substitution of the KST1 by the AKT3 pore led to less pronounced rectification properties of KST1/(p)AKT3 compared with wild-type KST1. Besides the voltage dependence, the interaction between the chimera and extracellular H(+) and Ca(2)+ resembled the properties of the inserted rather than the respective wild-type pore. Whereas AKT3/(p)KST1 was acid activated and Ca(2)+ insensitive, extracellular protons and Ca(2)+ inhibited KST1/(p)AKT3. The regulation of the chimeric channels by cytoplasmic protons followed the respective wild-type backbone of the chimeric channels, indicating that the intracellular pH sensor is located outside the P domain. We thus conclude that essential elements for external pH and Ca(2)+ regulation and for the rectification of voltage-dependent K(+) uptake channels are located within the channel pore.
Ache,
GORK, a delayed outward rectifier expressed in guard cells of Arabidopsis thaliana, is a K(+)-selective, K(+)-sensing ion channel.
2000, Pubmed,
Xenbase
Ache,
GORK, a delayed outward rectifier expressed in guard cells of Arabidopsis thaliana, is a K(+)-selective, K(+)-sensing ion channel.
2000,
Pubmed
,
Xenbase
Anderson,
Functional expression of a probable Arabidopsis thaliana potassium channel in Saccharomyces cerevisiae.
1992,
Pubmed
Becker,
Changes in voltage activation, Cs+ sensitivity, and ion permeability in H5 mutants of the plant K+ channel KAT1.
1996,
Pubmed
,
Xenbase
Brüggemann,
Pronounced differences between the native K+ channels and KAT1 and KST1 alpha-subunit homomers of guard cells.
1999,
Pubmed
,
Xenbase
Cao,
Amino terminus and the first four membrane-spanning segments of the Arabidopsis K+ channel KAT1 confer inward-rectification property of plant-animal chimeric channels.
1995,
Pubmed
,
Xenbase
Chanda,
Transplanting the N-terminus from Kv1.4 to Kv1.1 generates an inwardly rectifying K+ channel.
1999,
Pubmed
,
Xenbase
Chiara,
A small domain in the N terminus of the regulatory alpha-subunit Kv2. 3 modulates Kv2.1 potassium channel gating.
1999,
Pubmed
Czempinski,
New structure and function in plant K+ channels: KCO1, an outward rectifier with a steep Ca2+ dependency.
1997,
Pubmed
Doyle,
The structure of the potassium channel: molecular basis of K+ conduction and selectivity.
1998,
Pubmed
Dreyer,
Plant K+ channel alpha-subunits assemble indiscriminately.
1997,
Pubmed
,
Xenbase
Dreyer,
Single mutations strongly alter the K+-selective pore of the K(in) channel KAT1.
1998,
Pubmed
,
Xenbase
Durell,
Structural models of the transmembrane region of voltage-gated and other K+ channels in open, closed, and inactivated conformations.
1998,
Pubmed
Gauss,
Molecular identification of a hyperpolarization-activated channel in sea urchin sperm.
1998,
Pubmed
Gaymard,
Identification and disruption of a plant shaker-like outward channel involved in K+ release into the xylem sap.
1998,
Pubmed
,
Xenbase
Hedrich,
Inward rectifier potassium channels in plants differ from their animal counterparts in response to voltage and channel modulators.
1995,
Pubmed
,
Xenbase
Hoth,
Mutational analysis of functional domains within plant K+ uptake channels.
1997,
Pubmed
,
Xenbase
Hoth,
Susceptibility of the guard-cell K(+)-uptake channel KST1 to Zn(2+) requires histidine residues in the S3-S4 linker and in the channel pore.
1999,
Pubmed
,
Xenbase
Hoth,
Distinct molecular bases for pH sensitivity of the guard cell K+ channels KST1 and KAT1.
1999,
Pubmed
,
Xenbase
Hoth,
Molecular basis of plant-specific acid activation of K+ uptake channels.
1997,
Pubmed
,
Xenbase
Lacombe,
A shaker-like K(+) channel with weak rectification is expressed in both source and sink phloem tissues of Arabidopsis.
2000,
Pubmed
,
Xenbase
Loots,
Protein rearrangements underlying slow inactivation of the Shaker K+ channel.
1998,
Pubmed
Ludwig,
A family of hyperpolarization-activated mammalian cation channels.
1998,
Pubmed
Marten,
Voltage-dependent gating characteristics of the K+ channel KAT1 depend on the N and C termini.
1997,
Pubmed
Marten,
The N-terminus of the K channel KAT1 controls its voltage-dependent gating by altering the membrane electric field.
1998,
Pubmed
,
Xenbase
Marten,
AKT3, a phloem-localized K+ channel, is blocked by protons.
1999,
Pubmed
,
Xenbase
Müller-Röber,
Cloning and electrophysiological analysis of KST1, an inward rectifying K+ channel expressed in potato guard cells.
1995,
Pubmed
,
Xenbase
Papazian,
Alteration of voltage-dependence of Shaker potassium channel by mutations in the S4 sequence.
1991,
Pubmed
,
Xenbase
Perozo,
S4 mutations alter gating currents of Shaker K channels.
1994,
Pubmed
,
Xenbase
Philippar,
Auxin-induced K+ channel expression represents an essential step in coleoptile growth and gravitropism.
1999,
Pubmed
,
Xenbase
Schachtman,
Expression of an inward-rectifying potassium channel by the Arabidopsis KAT1 cDNA.
1992,
Pubmed
,
Xenbase
Sentenac,
Cloning and expression in yeast of a plant potassium ion transport system.
1992,
Pubmed
Tang,
Histidine(118) in the S2-S3 linker specifically controls activation of the KAT1 channel expressed in Xenopus oocytes.
2000,
Pubmed
,
Xenbase
Terlau,
Amino terminal-dependent gating of the potassium channel rat eag is compensated by a mutation in the S4 segment.
1997,
Pubmed
,
Xenbase
Thiel,
Small inward rectifying K+ channels in coleoptiles: inhibition by external Ca2+ and function in cell elongation.
1996,
Pubmed
Tytgat,
Reversal of rectification and alteration of selectivity and pharmacology in a mammalian Kv1.1 potassium channel by deletion of domains S1 to S4.
1994,
Pubmed
,
Xenbase
Uozumi,
Determination of transmembrane topology of an inward-rectifying potassium channel from Arabidopsis thaliana based on functional expression in Escherichia coli.
1998,
Pubmed
Wegner,
Properties of the K+ inward rectifier in the plasma membrane of xylem parenchyma cells from barley roots: effects of TEA+, Ca2+, Ba2+ and La3+.
1994,
Pubmed
Yusaf,
Measurement of the movement of the S4 segment during the activation of a voltage-gated potassium channel.
1996,
Pubmed
,
Xenbase
