Tuning the ion selectivity of two-pore channels.

ABSTRACT: Organellar two-pore channels (TPCs) contain two copies of a Shaker-like six-transmembrane (6-TM) domain in each subunit and are ubiquitously expressed in plants and animals. Interestingly, plant and animal TPCs share high sequence similarity in the filter region, yet exhibit drastically different ion selectivity. Plant TPC1 functions as a nonselective cation channel on the vacuole membrane, whereas mammalian TPC channels have been shown to be endo/lysosomal Na⁺-selective or Ca²⁺-release channels. In this study, we performed systematic characterization of the ion selectivity of TPC1 from Arabidopsis thaliana (AtTPC1) and compared its selectivity with the selectivity of human TPC2 (HsTPC2). We demonstrate that AtTPC1 is selective for Ca²⁺ over Na⁺,

SUBMITTER: Guo J 

PROVIDER: S-EPMC5293054 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature