Potassium (K⁺) is an important nutrient for plants. It serves as a cofactor of various enzymes and as the major inorganic solute maintaining plant cell turgor. In a recent study, an as yet unknown role of K⁺ in plant homeostasis was shown. It was demonstrated that K⁺ gradients in vascular tissues can serve as an energy source for phloem (re)loading processes and that the voltage-gated K⁺ channels of the AKT2-type play a unique role in this process. The AKT2 channel can be converted by phosphorylation of specific serine residues (S210 and S329) into a non-rectifying channel that allows a rapid efflux of K⁺ from the sieve element/companion cells (SE/CC) complex. The energy of this flux is used by other transporters for phloem (re)loading processes. Nonetheless, the results do indicate that post-translational modifications at S210 and S329 alone cannot explain AKT2 regulation. Here, we discuss the existence of multiple post-translational modification steps that work in concert to convert AKT2 from an inward-rectifying into a non-rectifying K⁺ channel.

Item Type:	Refereed Article
Keywords:	potassium, channel, potassium channel, AKT2, phloem (re)loading, post-translational modifications, potassium battery
Research Division:	Biological Sciences
Research Group:	Plant Biology
Research Field:	Plant Physiology
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Environmentally Sustainable Plant Production
Objective Field:	Management of Gaseous Waste from Plant Production (excl. Greenhouse Gases)
UTAS Author:	Cuin, TA (Dr Tracey Cuin)
ID Code:	127012
Year Published:	2011
Web of Science® Times Cited:	80
Deposited By:	Agriculture and Food Systems
Deposited On:	2018-07-06
Last Modified:	2018-08-13
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