TbIRK is a signature sequence free potassium channel from Trypanosoma brucei locating to acidocalcisomes.

ABSTRACT: Potassium channels from prokaryotes and eukaryotes are usually recognized by a typical amino acid sequence TXTGY(F)G representing the ionic selectivity filter. Using a screening approach with ion channel family profiles but without the above motif, we identified a gene in Trypanosoma brucei that exhibits homology to inward rectifying potassium channels. We report here cloning of this ion channel named TbIRK. The protein is localized to acidocalcisomes in procyclic and in bloodstream form parasites. Functional properties of this channel were established after expression in Xenopus oocytes. Currents recorded in potassium medium show inward rectification and little time dependence. Surprisingly, this channel retains selectivity for potassium ions over sodium ions >7, in spite of the lack of t

SUBMITTER: Steinmann ME 

PROVIDER: S-EPMC5429665 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature