Abstract
NHA1 encodes a K(+) (Na(+))/H(+) antiporter in the plasma membrane of Saccharomyces cerevisiae. We report that cells expressing the NHA1 gene contained less K(+) than the mutant lacking the gene when grown without K(+) limitation. They also grew better at low K(+) and showed higher affinity of transport than the nha1 strain. In agreement with the function of an electroneutral cation/H(+) antiporter, the effect was only observed at acidic pH. The improved growth and transport depended on the presence of Trk1p (the main K(+) influx system) and did not require the product of TRK2. We propose that Nha1p regulates the potassium content of the cell and, as a consequence, can affect the activity of the main K(+) influx system (Trk1p).
Copyright 2002 John Wiley & Sons, Ltd.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Biological Transport
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Carrier Proteins / genetics
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Carrier Proteins / physiology
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Cation Transport Proteins*
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Culture Media
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Hydrogen-Ion Concentration
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Membrane Proteins / physiology
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Mutation
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Potassium / metabolism*
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Rubidium / metabolism
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Saccharomyces cerevisiae / growth & development
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Saccharomyces cerevisiae / metabolism*
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Saccharomyces cerevisiae Proteins*
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Sodium-Hydrogen Exchangers / genetics
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Sodium-Hydrogen Exchangers / metabolism*
Substances
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Carrier Proteins
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Cation Transport Proteins
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Culture Media
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Membrane Proteins
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NHA1 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins
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Sodium-Hydrogen Exchangers
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TRK1 protein, S cerevisiae
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Rubidium
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Potassium