title: The K (+) battery-regulating Arabidopsis K (+) channel AKT2 is under the control of multiple post-translational steps.
abstract: 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.
authors: Institute of Biochemistry and Biology, University of Potsdam, Potsdam-Golm, Germany.
authors: Michael
authors: M
authors: Sandmann
authors: Kamil
authors: K
authors: Skłodowski
authors: Pawel
authors: P
authors: Gajdanowicz
authors: Erwan
authors: E
authors: Michard
authors: Marcio
authors: M
authors: Rocha
authors: Judith L
authors: JL
authors: Gomez-Porras
authors: Wendy
authors: W
authors: González
authors: Luiz Gustavo Guedes
authors: LG
authors: Corrêa
authors: Santiago J
authors: SJ
authors: Ramírez-Aguilar
authors: Tracey Ann
authors: TA
authors: Cuin
authors: Joost T
authors: JT
authors: van Dongen
authors: Jean-Baptiste
authors: JB
authors: Thibaud
authors: Ingo
authors: I
authors: Dreyer
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000235:genetics / Q000502:physiology
chemical_list: C097485:AKT2 protein, Arabidopsis; D029681:Arabidopsis Proteins; D015221:Potassium Channels; D011188:Potassium