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Mammalian NHE2 Na + /H + exchanger mediates efflux of potassium upon heterologous expression in yeast
Author(s) -
Flegelova Hana,
Sychrova Hana
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.07.046
Subject(s) - efflux , yeast , saccharomyces cerevisiae , heterologous expression , potassium , chemistry , membrane , alkali metal , biochemistry , mutant , biophysics , biology , recombinant dna , gene , organic chemistry
Na + /H + exchangers form a broad family of transporters that mediate opposing fluxes of alkali metal cations and protons across cell membranes. They play multiple roles in different organisms (protection from toxic cations, regulation of cell volume or pH). Rat NHE2 exchanger was expressed in a Saccharomyces cerevisiae mutant strain lacking its own exporters of alkali metal cations. Though most of the overexpressed NHE2 remained entrapped in the secretory pathway, part of it reached the plasma membrane and mediated K + efflux from the yeast. We demonstrate for the first time that a mammalian Na + /H + exchanger transports alkali metal cations in yeast in the opposite direction than in mammalian cells, and that the substrate specificity of the rat NHE2 exchanger is limited only to potassium cations upon expression in yeast cells.