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Arabidopsis protein kinase PKS5 inhibits the plasma membrane H+-ATPase by preventing interaction with 14-3-3 protein


Fuglsang, AT and Guo, Yan and Cuin, TA and Qui, Quansheng and Song, Chunpeng and Kristiansen, KA and Bych, K and Schulz, A and Shabala, SN and Schumaker, KS and Palmgren, MG and Zhu, JianKang, Arabidopsis protein kinase PKS5 inhibits the plasma membrane H+-ATPase by preventing interaction with 14-3-3 protein, The Plant Cell, 19, (5) pp. 1617-1634. ISSN 1040-4651 (2007) [Refereed Article]

DOI: doi:10.1105/tpc.105.035626


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. © 2007 American Society of Plant Biologists.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the environmental sciences
UTAS Author:Cuin, TA (Dr Tracey Cuin)
UTAS Author:Shabala, SN (Professor Sergey Shabala)
ID Code:48792
Year Published:2007
Web of Science® Times Cited:297
Deposited By:Agricultural Science
Deposited On:2007-08-01
Last Modified:2009-10-26

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