This Article Full Text Full Text (PDF) All Versions of this Article: 19/5/1617    most recent tpc.105.035626v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Fuglsang, A. T. Articles by Zhu, J.-K. Search for Related Content PubMed PubMed Citation Articles by Fuglsang, A. T. Articles by Zhu, J.-K. Agricola Articles by Fuglsang, A. T. Articles by Zhu, J.-K.

Arabidopsis Protein Kinase PKS5 Inhibits the Plasma Membrane H⁺-ATPase by Preventing Interaction with 14-3-3 Protein

^a Department of Plant Biology, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
^b Department of Plant Sciences, University of Arizona, Tucson, Arizona 85721
^c School of Agricultural Sciences, University of Tasmania, Hobart TAS 7001, Australia

³ To whom correspondence should be addressed. E-mail palmgren{at}life.ku.dk; fax 45-3528 3365.

Regulation of the trans-plasma membrane pH gradient is an important part of plant responses to several hormonal and environmental cues, including auxin, blue light, and fungal elicitors. However, little is known about the signaling components that mediate this regulation. Here, we report that an Arabidopsis thaliana Ser/Thr protein kinase, PKS5, is a negative regulator of the plasma membrane proton pump (PM H⁺-ATPase). Loss-of-function pks5 mutant plants are more tolerant of high external pH due to extrusion of protons to the extracellular space. PKS5 phosphorylates the PM H⁺-ATPase AHA2 at a novel site, Ser-931, in the C-terminal regulatory domain. Phosphorylation at this site inhibits interaction between the PM H⁺-ATPase and an activating 14-3-3 protein in a yeast expression system. We show that PKS5 interacts with the calcium binding protein SCaBP1 and that high external pH can trigger an increase in the concentration of cytosolic-free calcium. These results suggest that PKS5 is part of a calcium-signaling pathway mediating PM H⁺-ATPase regulation.

This article has been cited by other articles:

				O. Batistic, N. Sorek, S. Schultke, S. Yalovsky, and J. Kudla Dual Fatty Acyl Modification Determines the Localization and Plasma Membrane Targeting of CBL/CIPK Ca2+ Signaling Complexes in Arabidopsis PLANT CELL, May 1, 2008; 20(5): 1346 - 1362. [Abstract] [Full Text] [PDF]

				A. Wasilewska, F. Vlad, C. Sirichandra, Y. Redko, F. Jammes, C. Valon, N. F. d. Frey, and J. Leung An Update on Abscisic Acid Signaling in Plants and More ... Mol Plant, March 1, 2008; 1(2): 198 - 217. [Abstract] [Full Text] [PDF]

				F. Gevaudant, G. Duby, E. von Stedingk, R. Zhao, P. Morsomme, and M. Boutry Expression of a Constitutively Activated Plasma Membrane H+-ATPase Alters Plant Development and Increases Salt Tolerance Plant Physiology, August 1, 2007; 144(4): 1763 - 1776. [Abstract] [Full Text] [PDF]