Calcium-dependent modulation and plasma membrane targeting of the AKT2 potassium channel by the CBL4/CIPK6 calcium sensor/protein kinase complex

Held, Katrin; Pascaud, Francois; Eckert, Christian; Gajdanowicz, Pawel; Hashimoto, Kenji; Corratge-Faillie, Claire; Offenborn, Jan Niklas; Lacombe, Benoit; Dreyer, Ingo; Thibaud, Jean-Baptiste; Kudla, Joerg


Potassium (K(+)) channel function is fundamental to many physiological processes. However, components and mechanisms regulating the activity of plant K(+) channels remain poorly understood. Here, we show that the calcium (Ca(2+)) sensor CBL4 together with the interacting protein kinase CIPK6 modulates the activity and plasma membrane (PM) targeting of the K(+) channel AKT2 from Arabidopsis thaliana by mediating translocation of AKT2 to the PM in plant cells and enhancing AKT2 activity in oocytes. Accordingly, akt2, cbl4 and cipk6 mutants share similar developmental and delayed flowering phenotypes. Moreover, the isolated regulatory C-terminal domain of CIPK6 is sufficient for mediating CBL4- and Ca(2+)-dependent channel translocation from the endoplasmic reticulum membrane to the PM by a novel targeting pathway that is dependent on dual lipid modifications of CBL4 by myristoylation and palmitoylation. Thus, we describe a critical mechanism of ion-channel regulation where a Ca(2+) sensor modulates K(+) channel activity by promoting a kinase interaction-dependent but phosphorylation-independent translocation of the channel to the PM.

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Título según WOS: ID WOS:000292322900013 Not found in local WOS DB
Título de la Revista: CELL RESEARCH
Volumen: 21
Número: 7
Fecha de publicación: 2011
Página de inicio: 1116
Página final: 1130


Notas: ISI