Amino acids control ammonia pulses in yeast colonies

• Published in: Biochemical and biophysical research communications 2002-06, Vol.294 (5), p.962-967
• Main Authors: Zikánová, Blanka, Kuthan, Martin, Řičicová, Markéta, Forstová, Jitka, Palková, Zdena
• Format: Article
• Language: English
• Subjects: Amino acid permeases; Amino Acid Transport Systems - genetics; Amino Acid Transport Systems - physiology; Amino Acids - pharmacology; Ammonia - metabolism; Ammonia signalling; Ammonium permeases; Biological Transport; Candida - cytology; Candida - growth & development; Candida - metabolism; Carrier Proteins - genetics; Carrier Proteins - physiology; Intracellular Signaling Peptides and Proteins; Membrane Proteins - genetics; Membrane Proteins - physiology; Saccharomyces cerevisiae - cytology; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins; SPS sensor; Yeast colonies; Yeasts - growth & development; Yeasts - metabolism
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(02)00589-2

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.