Role of hexose transport in control of glycolytic flux in Saccharomyces cerevisiae
Journal article, 2004

The yeast Saccharomyces cerevisiae predominantly ferments glucose to ethanol at high external glucose concentrations, irrespective of the presence of oxygen. In contrast, at low external glucose concentrations and in the presence of oxygen, as in a glucose-limited chemostat, no ethanol is produced. The importance of the external glucose concentration suggests a central role for the affinity and maximal transport rates of yeast's glucose transporters in the control of ethanol production. Here we present a series of strains producing functional chimeras between the hexose transporters Hxt1 and Hxt7, each of which has distinct glucose transport characteristics. The strains display a range of decreasing glycollytic rates resulting in a proportional decrease in ethanol production. Using these strains, we show for the first time that at high glucose levels, the glucose uptake capacity of wild-type S. cerevisiae does not control glycolytic flux during exponential batch growth. In contrast, our chimeric Hxt transporters control the rate of glycollysis to a high degree. Strains whose glucose uptake is mediated by these chimeric transporters will undoubtedly provide a powerful tool with which to examine in detail the mechanism underlying the switch between fermentation and respiration in S. cerevisiae and will provide new tools for the control of industrial fermentations.

yeast-cells

metabolism

growth

chemostat cultures

enzymes

sugar transporters

hxt genes

overexpression

glucose-transport

catabolite repression

Author

Karin Elbing

Chalmers, Department of Chemistry and Bioscience, Molecular Biotechnology

Christer Larsson

Chalmers, Department of Chemistry and Bioscience, Molecular Biotechnology

R Bill

Aston University

Eva Albers

Chalmers, Department of Chemistry and Bioscience, Molecular Biotechnology

J. L. Snoep

Stellenbosch University

E Boles

Goethe University Frankfurt

Stefan Hohmann

University of Gothenburg

Lena Gustafsson

Chalmers, Department of Chemistry and Bioscience, Molecular Biotechnology

Applied and Environmental Microbiology

0099-2240 (ISSN) 1098-5336 (eISSN)

Vol. 70 9 5323-5330

Subject Categories

Biochemistry and Molecular Biology

DOI

10.1128/AEM.70.9.5323-5330.2004

More information

Latest update

3/29/2018