Stolz, Juergen and Woehrmann, Heike J. P. and Vogl, Christian (2005) Amiloride uptake and toxicity in fission yeast are caused by the pyridoxine transporter encoded by bsu1(+) (car1(+)). EUKARYOTIC CELL, 4 (2). pp. 319-326. ISSN 1535-9778,
Full text not available from this repository. (Request a copy)Abstract
Amiloride, a diuretic drug that acts by inhibition of various sodium transporters, is toxic to the fission yeast Schizosaccharomyces pombe. Previous work has established that amiloride sensitivity is caused by expression of car1(+), which encodes a protein with similarity to plasma membrane drug/proton antiporters from the multidrug resistance family. Here we isolated car1(+) by complementation of Saccharomyces cerevisiae mutants that are deficient in pyridoxine biosynthesis and uptake. Our data show that Car1p represents a new high-affinity, plasma membrane-localized import carrier for pyridoxine, pyridoxal, and pyridoxamine. We therefore propose the gene name bsu1(+) (for vitamin B, uptake) to replace car1(+). Bsu1p displays an acidic pH optimum and is inhibited by various protonophores, demonstrating that the protein works as a proton symporter. The expression of bsu1(+) is associated with amiloride sensitivity and pyridoxine uptake in both S. cerevisiae and S. pombe cells. Moreover, amiloride acts as a competitor of pyridoxine uptake, demonstrating that both compounds are substrates of Bsu1p. Taken together, our data show that S. pombe and S. cerevisiae possess unrelated plasma membrane pyridoxine transporters. The S. pombe protein may be structurally related to the unknown human pyridoxine transporter, which is also inhibited by amiloride.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | MAJOR FACILITATOR SUPERFAMILY; SCHIZOSACCHAROMYCES-POMBE; SACCHAROMYCES-CEREVISIAE; HETEROLOGOUS MODULES; BACILLUS-SUBTILIS; ACTIVE-TRANSPORT; COMPLETE GENOME; GENE FAMILIES; ION-TRANSPORT; BIOSYNTHESIS; |
| Subjects: | 500 Science > 580 Botanical sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Pflanzenwissenschaften > Lehrstuhl für Zellbiologie und Pflanzenphysiologie (Prof. Dr. Klaus Grasser) |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 31 May 2021 05:25 |
| Last Modified: | 31 May 2021 05:25 |
| URI: | https://pred.uni-regensburg.de/id/eprint/36514 |
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