The yeast Saccharomyces cerevisiae does not sequester chloride but can express a functional mammalian chloride channel

Chloride uptake into yeast was measured as a function of pH, A small amount of uptake was seen at pH values of 3.0 and 4.0; at pH 6.0 chloride uptake was substantially less than the uptake of phosphate and rubidium. Because c hloride uptake is inefficient, we expressed the putative mammalian chloride channel, pI(Cln), in yeast and observed a chloride-selective current when total membrane protein was reconstituted into lipid bilayers. The current w as inhibited by a specific chloride channel blocker, 5-nitro-2-(3-phenylpro pylamino)-benzoic acid. These results suggest that yeast may serve as a mea ns to characterize chloride channels from other organisms. (C) 1999 Federat ion of European Microbiological Societies. Published by Elsevier Science B. V. All rights reserved.