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Updated: Aug 18, 2026

Extraction and Quantification of Soluble, Radiolabeled Inositol Polyphosphates from Different Plant Species using SAX-HPLC
Published on: June 26, 2020
An essential function of phosphatidylinositol phosphates in activation of plant shaker-type K+ channels
Kun Liu1, Legong Li, Sheng Luan
1Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
Abstract:
A prominent regulatory property of plant shaker-type K+ channels is the 'rundown' that causes channel closure upon membrane excision from the cell, implicating intracellular factor(s) in maintaining channel activity. One such factor has been identified as hydrolysable ATP-Mg although the mechanism for ATP function remains unknown. Here we report identification of phosphatidylinositol (PI) phosphates (PIPs) as essential regulators for the voltage-dependent and -independent activation of plant shaker-type channels such as SKOR, an outward rectifying K+ channel. Inhibition of PI kinase activity abolished the function of ATP-Mg in restoration of rundown channel activity, demonstrating that PIPs production by PI kinases and ATP-Mg underlies ATP-induced activation of the rundown channel. We also identified aluminum block as a common feature of the plant shaker-type channels and provided evidence that aluminum block of these channels may result from Al interaction with PIPs.
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