Allelic variation in the vacuolar TPK1 channel affects its calcium dependence and may impact on stomatal conductance.

Tom N Hartley, Frans J M Maathuis

FEBS letters 2016 Jan

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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. © 2015 Federation of European Biochemical Societies.

Citation

Tom N Hartley, Frans J M Maathuis. Allelic variation in the vacuolar TPK1 channel affects its calcium dependence and may impact on stomatal conductance. FEBS letters. 2016 Jan;590(1):110-7