The Potassium Channel KAT1 Is Activated by Plant and Animal 14-3-3 Proteins

14-3-3 proteins modulate the plant inward rectifier K+ channel KAT1 heterologously expressed in Xenopus oocytes. Injection of recombinant plant 14-3-3 proteins into oocytes shifted the activation curve of KAT1 by +11 mV and increased the τon. KAT1 was also modulated by 14-3-3 proteins of Xenopus ooc...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 2006-11, Vol.281 (47), p.35735-35741
Main Authors: Sottocornola, Barbara, Visconti, Sabina, Orsi, Sara, Gazzarrini, Sabrina, Giacometti, Sonia, Olivari, Claudio, Camoni, Lorenzo, Aducci, Patrizia, Marra, Mauro, Abenavoli, Alessandra, Thiel, Gerhard, Moroni, Anna
Format: Article
Language:English
Subjects:
14-3-3 Proteins - metabolism
Animals
Arabidopsis Proteins - metabolism
Arabidopsis Proteins - physiology
Cell Membrane - metabolism
Cesium - metabolism
Electrophysiology - methods
Escherichia coli - metabolism
Freshwater
Ion Channel Gating
Mutation
Oocytes - metabolism
Patch-Clamp Techniques
Potassium Channels, Inwardly Rectifying - chemistry
Potassium Channels, Inwardly Rectifying - metabolism
Potassium Channels, Inwardly Rectifying - physiology
raf Kinases - chemistry
Recombinant Proteins - chemistry
Xenopus
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:14-3-3 proteins modulate the plant inward rectifier K+ channel KAT1 heterologously expressed in Xenopus oocytes. Injection of recombinant plant 14-3-3 proteins into oocytes shifted the activation curve of KAT1 by +11 mV and increased the τon. KAT1 was also modulated by 14-3-3 proteins of Xenopus oocytes. Titration of the endogenous 14-3-3 proteins by injection of the peptide Raf 621p resulted in a strong decrease in KAT1 current (∼70% at –150 mV). The mutation K56E performed on plant protein 14-3-3 in a highly conserved recognition site prevented channel activation. Because the maximal conductance of KAT1 was unaffected by 14-3-3, we can exclude that they act by increasing the number of channels, thus ruling out any effect of these proteins on channel trafficking and/or insertion into the oocyte membrane. 14-3-3 proteins also increased KAT1 current in inside-out patches, suggesting a direct interaction with the channel. Direct interaction was confirmed by overlay experiments with radioactive 14-3-3 on oocyte membranes expressing KAT1.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M603361200