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The Saccharomyces cerevisiae alcohol acetyl transferase gene ATF1 is a target of the cAMP/PKA and FGM nutrient-signalling pathways
The ATF1-encoded Saccharomyces cerevisiae yeast alcohol acetyl transferase I is responsible for the formation of several different volatile acetate esters during fermentations. A number of these volatile esters, e.g. ethyl acetate and isoamyl acetate, are amongst the most important aroma compounds i...
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Published in: | FEMS yeast research 2003-12, Vol.4 (3), p.285-296 |
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Main Authors: | , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Online Access: | Get full text |
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Summary: | The
ATF1-encoded
Saccharomyces cerevisiae yeast alcohol acetyl transferase I is responsible for the formation of several different volatile acetate esters during fermentations. A number of these volatile esters, e.g. ethyl acetate and isoamyl acetate, are amongst the most important aroma compounds in fermented beverages such as beer and wine. Manipulation of the expression levels of
ATF1 in brewing yeast strains has a significant effect on the ester profile of beer. Northern blot analysis of
ATF1 and its closely related homologue, Lg-
ATF1, showed that these genes were rapidly induced by the addition of glucose to anaerobically grown carbon-starved cells. This induction was abolished in a protein kinase A (PKA)-attenuated strain, while a PKA-overactive strain showed stronger
ATF1 expression, indicating that the Ras/cAMP/PKA signalling pathway is involved in this glucose induction. Furthermore, nitrogen was needed in the growth medium in order to maintain
ATF1 expression. Long-term activation of
ATF1 could also be obtained by the addition of the non-metabolisable amino acid homologue β-
L-alanine, showing that the effect of the nitrogen source did not depend on its metabolism. In addition to nutrient regulation,
ATF1 and Lg-
ATF1 expression levels were also affected by heat and ethanol stress. These findings help in the understanding of the effect of medium composition on volatile ester synthesis in industrial fermentations. In addition, the complex regulation provides new insights into the physiological role of Atf1p in yeast. |
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ISSN: | 1567-1356 1567-1364 |
DOI: | 10.1016/S1567-1356(03)00166-1 |