Send to

Choose Destination
Cell. 2006 Jun 30;125(7):1347-60.

A protein kinase, interacting with two calcineurin B-like proteins, regulates K+ transporter AKT1 in Arabidopsis.

Author information

State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, National Plant Gene Research Centre (Beijing), Beijing 100094, China.


Potassium is an essential mineral element for plant growth and development. Although it is known that plants absorb and transport K+ through membrane transporters, it remains unclear how these transporters are regulated. Here we show that the protein kinase CIPK23, encoded by the LKS1 gene, regulates K+ uptake under low-K+ conditions. Lesion of LKS1 significantly reduced K+ uptake and caused leaf chlorosis and growth inhibition, whereas overexpression of LKS1 significantly enhanced K+ uptake and tolerance to low K+. We demonstrate that CIPK23 directly phosphorylates the K+ transporter AKT1 and further find that CIPK23 is activated by the binding of two calcineurin B-like proteins, CBL1 and CBL9. We propose a model in which the CBL1/9-CIPK23 pathway ensures activation of AKT1 and enhanced K+ uptake under low-K+ conditions.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center