The Arabidopsis vacuolar two-pore K channel 1 (TPK1) interacts with the 1433 protein GRF6 (GF14-). Here, we report that this interaction requires activation of the 1433 binding motif in TPK1 by the calcium-dependent protein kinase CPK3. Cpk3 and tpk1 mutants displayed salt-sensitive phenotypes, providing evidence for an essential role of the vacuolar potassium channel TPK1 in Ca-2-dependent salt-stress adaptation.1433 proteins play an important role in the regulation of many cellular processes. The Arabidopsis vacuolar two-pore K channel 1 (TPK1) interacts with the 1433 protein GRF6 (GF14-). Upon phosphorylation of the putative binding motif in the N-terminus of TPK1, GRF6 binds to TPK1 and activates the potassium channel. In order to gain a deeper understanding of this 1433-mediated signal transduction, we set out to identify the respective kinases, which regulate the phosphorylation status of the 1433 binding motif in TPK1. Here, we report that the calcium-dependent protein kinases (CDPKs) can phosphorylate and thereby activate the 1433 binding motif in TPK1. Focusing on the stress-activated kinase CPK3, we visualized direct and specific interaction of TPK1 with the kinase at the tonoplast in vivo. In line with its proposed role in K homeostasis, TPK1 phosphorylation was found to be induced by salt stress in planta, and both cpk3 and tpk1 mutants displayed salt-sensitive phenotypes. Molecular modeling of the TPK1CPK3 interaction domain provided mechanistic insights into TPK1 stress-regulated phosphorylation responses and pinpointed two arginine residues in the N-terminal 1433 binding motif in TPK1 critical for kinase interaction. Taken together, our studies provide evidence for an essential role of the vacuolar potassium channel TPK1 in salt-stress adaptation as a target of calcium-regulated stress signaling pathways involving Ca-2, Ca-2-dependent kinases, and 1433 proteins.
%0 Journal Article
%1 RN1084
%A Latz, A.
%A Mehlmer, N.
%A Zapf, S.
%A Mueller, T. D.
%A Wurzinger, B.
%A Pfister, B.
%A Csaszar, E.
%A Hedrich, R.
%A Teige, M.
%A Becker, D.
%D 2013
%J Molecular Plant
%K channel myOwn potassium
%N 4
%P 1274-1289
%R 10.1093/mp/sss158
%T Salt Stress Triggers Phosphorylation of the
Vacuolar K Channel TPK1 by Calcium-Dependent Protein Kinases (CDPKs)
%U /brokenurl#<Go to ISI>://WOS:000322410700020
%V 6
%X The Arabidopsis vacuolar two-pore K channel 1 (TPK1) interacts with the 1433 protein GRF6 (GF14-). Here, we report that this interaction requires activation of the 1433 binding motif in TPK1 by the calcium-dependent protein kinase CPK3. Cpk3 and tpk1 mutants displayed salt-sensitive phenotypes, providing evidence for an essential role of the vacuolar potassium channel TPK1 in Ca-2-dependent salt-stress adaptation.1433 proteins play an important role in the regulation of many cellular processes. The Arabidopsis vacuolar two-pore K channel 1 (TPK1) interacts with the 1433 protein GRF6 (GF14-). Upon phosphorylation of the putative binding motif in the N-terminus of TPK1, GRF6 binds to TPK1 and activates the potassium channel. In order to gain a deeper understanding of this 1433-mediated signal transduction, we set out to identify the respective kinases, which regulate the phosphorylation status of the 1433 binding motif in TPK1. Here, we report that the calcium-dependent protein kinases (CDPKs) can phosphorylate and thereby activate the 1433 binding motif in TPK1. Focusing on the stress-activated kinase CPK3, we visualized direct and specific interaction of TPK1 with the kinase at the tonoplast in vivo. In line with its proposed role in K homeostasis, TPK1 phosphorylation was found to be induced by salt stress in planta, and both cpk3 and tpk1 mutants displayed salt-sensitive phenotypes. Molecular modeling of the TPK1CPK3 interaction domain provided mechanistic insights into TPK1 stress-regulated phosphorylation responses and pinpointed two arginine residues in the N-terminal 1433 binding motif in TPK1 critical for kinase interaction. Taken together, our studies provide evidence for an essential role of the vacuolar potassium channel TPK1 in salt-stress adaptation as a target of calcium-regulated stress signaling pathways involving Ca-2, Ca-2-dependent kinases, and 1433 proteins.
@article{RN1084,
abstract = {The Arabidopsis vacuolar two-pore K channel 1 (TPK1) interacts with the 1433 protein GRF6 (GF14-). Here, we report that this interaction requires activation of the 1433 binding motif in TPK1 by the calcium-dependent protein kinase CPK3. Cpk3 and tpk1 mutants displayed salt-sensitive phenotypes, providing evidence for an essential role of the vacuolar potassium channel TPK1 in Ca-2-dependent salt-stress adaptation.1433 proteins play an important role in the regulation of many cellular processes. The Arabidopsis vacuolar two-pore K channel 1 (TPK1) interacts with the 1433 protein GRF6 (GF14-). Upon phosphorylation of the putative binding motif in the N-terminus of TPK1, GRF6 binds to TPK1 and activates the potassium channel. In order to gain a deeper understanding of this 1433-mediated signal transduction, we set out to identify the respective kinases, which regulate the phosphorylation status of the 1433 binding motif in TPK1. Here, we report that the calcium-dependent protein kinases (CDPKs) can phosphorylate and thereby activate the 1433 binding motif in TPK1. Focusing on the stress-activated kinase CPK3, we visualized direct and specific interaction of TPK1 with the kinase at the tonoplast in vivo. In line with its proposed role in K homeostasis, TPK1 phosphorylation was found to be induced by salt stress in planta, and both cpk3 and tpk1 mutants displayed salt-sensitive phenotypes. Molecular modeling of the TPK1CPK3 interaction domain provided mechanistic insights into TPK1 stress-regulated phosphorylation responses and pinpointed two arginine residues in the N-terminal 1433 binding motif in TPK1 critical for kinase interaction. Taken together, our studies provide evidence for an essential role of the vacuolar potassium channel TPK1 in salt-stress adaptation as a target of calcium-regulated stress signaling pathways involving Ca-2, Ca-2-dependent kinases, and 1433 proteins.},
added-at = {2024-02-14T14:38:32.000+0100},
author = {Latz, A. and Mehlmer, N. and Zapf, S. and Mueller, T. D. and Wurzinger, B. and Pfister, B. and Csaszar, E. and Hedrich, R. and Teige, M. and Becker, D.},
biburl = {https://www.bibsonomy.org/bibtex/2f9c3d253e9b974c00b052e99735aec3e/rainerhedrich_2},
doi = {10.1093/mp/sss158},
interhash = {774876b137f719fffe491056a03c7b94},
intrahash = {f9c3d253e9b974c00b052e99735aec3e},
issn = {1674-2052},
journal = {Molecular Plant},
keywords = {channel myOwn potassium},
note = {191kb
Times Cited:139
Cited References Count:82},
number = 4,
pages = {1274-1289},
timestamp = {2024-02-14T14:38:32.000+0100},
title = {Salt Stress Triggers Phosphorylation of the
Vacuolar K Channel TPK1 by Calcium-Dependent Protein Kinases (CDPKs)},
type = {Journal Article},
url = {/brokenurl#<Go to ISI>://WOS:000322410700020},
volume = 6,
year = 2013
}