Allelic variation in the vacuolar TPK1 channel affects its calcium dependence and may impact on stomatal conductance
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Updated: Mar 27, 2026

Author Spotlight: Image-Based Methods to Study Membrane Trafficking Events in Stomatal Lineage Cells
Published on: May 12, 2023
Tom N Hartley1, Frans J M Maathuis1
1Department of Biology, University of York, UK.
Abstract:
Natural variation can be exploited to identify allelic variants of proteins. In this study, patch clamp was used to determine transport properties of two AtTPK1 alleles from Landsberg and Kas-2 ecotypes. No difference in conductance or ion selectivity was observed but the Kas version of TPK1 showed different Ca(2+) dependence in its open probability compared to Ler. Leaves from Kas showed lower rates of water loss than those of Ler, in either the absence or presence of ABA, an observation that is consistent with higher TPK1 channel activity at comparable cytoplasmic Ca(2+) concentrations. A model that explains the results is presented.
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