Abstract
Individual yeast colonies produce pulses of volatile ammonia separated by phases of medium acidification. Colonies of Saccharomyces cerevisiae mutant defective in the general amino acid permease, Gap1p, exhibit decreased ammonia production. Mutations in the S. cerevisiae amino acid sensor SPS completely abolish the colony ammonia pulses. In contrast, the ammonia pulse production is independent of external concentrations of ammonium and of its uptake by the ammonium permeases Mep1p, Mep2p, and Mep3p. It is concluded that in S. cerevisiae colonies, the extracellular amino acids, but not the extracellular ammonium, serve as a source for volatile ammonia production. These phenomena are not restricted to S. cerevisiae, since we observe that extracellular levels of 8 out of the 20 tested amino acids are necessary for ammonia pulses produced by Candida mogii colonies.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Transport Systems / genetics
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Amino Acid Transport Systems / physiology
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Amino Acids / pharmacology*
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Ammonia / metabolism*
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Biological Transport
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Candida / cytology
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Candida / growth & development
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Candida / metabolism
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Carrier Proteins / genetics
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Carrier Proteins / physiology
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Intracellular Signaling Peptides and Proteins
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Membrane Proteins / genetics
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Membrane Proteins / physiology
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Saccharomyces cerevisiae / cytology
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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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Yeasts / growth & development*
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Yeasts / metabolism*
Substances
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Amino Acid Transport Systems
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Amino Acids
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Carrier Proteins
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Intracellular Signaling Peptides and Proteins
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Membrane Proteins
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PTR3 protein, S cerevisiae
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SSY1 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins
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Ammonia