Plant Cell
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via ISI Web of Science (17)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hoth, S.
Right arrow Articles by Hedrich, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hoth, S.
Right arrow Articles by Hedrich, R.
Agricola
Right arrow Articles by Hoth, S.
Right arrow Articles by Hedrich, R.
Plant Cell, Vol. 13, 943-952, April 2001, Copyright © 2001, American Society of Plant Physiologists

The Pore of Plant K+ Channels Is Involved in Voltage and pH Sensing: Domain-Swapping between Different K+ Channel {alpha}-Subunits

Stefan Hoth, Dietmar Geiger, Dirk Becker, and Rainer Hedrich
Molekulare Pflanzenphysiologie und Biophysik, Julius-von-Sachs-Institut für Biowissenschaften, Universität Würzburg, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany

Correspondence to: Rainer Hedrich, hedrich{at}botanik.uni-wuerzburg.de (E-mail), 49-931-8886157 (fax)

Plant K+ uptake channel types differ with respect to their voltage, Ca2+, 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 Ca2+ resembled the properties of the inserted rather than the respective wild-type pore. Whereas AKT3/(p)KST1 was acid activated and Ca2+ insensitive, extracellular protons and Ca2+ 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 Ca2+ regulation and for the rectification of voltage-dependent K+ uptake channels are located within the channel pore.




This article has been cited by other articles:


Home page
 J Exp BotHome page
L. Prokic, Z. Jovanovic, M. R. McAinsh, Z. Vucinic, and R. Stikic
Species-dependent changes in stomatal sensitivity to abscisic acid mediated by external pH
J. Exp. Bot., February 1, 2006; 57(3): 675 - 683.
[Abstract] [Full Text] [PDF]

Home page
 J. Gen. Physiol.Home page
E. Michard, B. Lacombe, F. Poree, B. Mueller-Roeber, H. Sentenac, J.-B. Thibaud, and I. Dreyer
A Unique Voltage Sensor Sensitizes the Potassium Channel AKT2 to Phosphoregulation
J. Gen. Physiol., November 28, 2005; 126(6): 605 - 617.
[Abstract] [Full Text] [PDF]

Home page
 J. Gen. Physiol.Home page
N. Ivashikina, R. Deeken, S. Fischer, P. Ache, and R. Hedrich
AKT2/3 Subunits Render Guard Cell K+ Channels Ca2+ Sensitive
J. Gen. Physiol., April 25, 2005; 125(5): 483 - 492.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
C. Picco, M. Bregante, A. Naso, P. Gavazzo, A. Costa, E. Formentin, P. Downey, F. Lo Schiavo, and F. Gambale
Histidines Are Responsible for Zinc Potentiation of the Current in KDC1 Carrot Channels
Biophys. J., January 1, 2004; 86(1): 224 - 234.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
K. Philippar, K. Buchsenschutz, M. Abshagen, I. Fuchs, D. Geiger, B. Lacombe, and R. Hedrich
The K+ Channel KZM1 Mediates Potassium Uptake into the Phloem and Guard Cells of the C4 Grass Zea mays
J. Biol. Chem., May 2, 2003; 278(19): 16973 - 16981.
[Abstract] [Full Text] [PDF]

Home page
 Plant CellHome page
D. Geiger, D. Becker, B. Lacombe, and R. Hedrich
Outer Pore Residues Control the H+ and K+ Sensitivity of the Arabidopsis Potassium Channel AKT3
PLANT CELL, August 1, 2002; 14(8): 1859 - 1868.
[Abstract] [Full Text] [PDF]

Home page
 Sci SignalHome page
N. V. Fedoroff
Cross-Talk in Abscisic Acid Signaling
Sci. Signal., July 9, 2002; 2002(140): re10 - re10.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications THE PLANT CELL PLANT PHYSIOLOGY
Copyright © 2001 by the American Society of Plant Biologists