Sugar transport in Saccharomyces cerevisiae

Lagunas, Rosario

doi:10.1016/0378-1097(93)90598-v

Cited by 124 publications

(132 citation statements)

References 134 publications

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“…In contrast, we did not observe such effects for maltose utilization. Since maltose is utilized by the same glycolytic pathway as glucose but differs in its uptake system [36] we consider this as suggesting an hexose-uptake defect in grrl cells. The utilization of galactose is also apparently unaffected [14, 151 ; our observations support this notion.…”

Section: Discussionmentioning

confidence: 99%

Glucose Uptake and Metabolism in grr1/cat80 Mutants of Sacharomyces cerevisiae

Özcan

Schulte

Freidel

et al. 1994

European Journal of Biochemistry

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Glucose repression in the yeast Saccharomyces cerevisiae designates a global regulatory system controlling the expression of various sets of genes required for the utilization of alternate carbon sources. In a screen, designed for the selection of mutants with reduced glycolytic flux we obtained isolates which were shown by complementation of the cloned wild-type gene to be allelic to the glucose repression mutants grrllcat80lcot2 previously described. We demonstrate that the grrl lesion lead to a concentration-dependent decrease in glycolytic flux on glucose. It is very likely that this is caused by a significant decrease in the expression of various genes encoding hexose transporters (HXTI,3) leading to a reduced glucose-uptake rate. In contrast, expression of the maltose permease gene (MALll) and maltose utilization is normal. There is indirect evidence that grrl affects the uptake of amino acids, and others have shown that the sugar-induced transport of divalent cations is impaired. These effects are not glucose-specific. We suggest that Grrl, a putative cytoplasmic protein, has a central function in the sensing of nutritional conditions for a variety of unrelated substances, and that relief from glucose repression may be a corollary of this defect in sensing.In the yeast Saccharomyces cerevisiae glucose or other readily fermentable carbon sources act as global regulators of growth and metabolism. These regulatory effects are executed partly at the transcriptional level. Glucose repression and glucose induction designate mechanisms that exert specific control on glucose-sensitive genes. Glucose-repressible genes include SUC2 (invertase) and genes that are required for the utilization of alternate carbohydrates (the GAL, MAL and MEL regulons required for the utilization of galactose, maltose and melibiose, respectively; for review see [l]), mitochondrial genes [2] and nuclear genes for mitochondrial and gluconeogenic functions [3]. Analysis of glucose induction at the gene expression level is less advanced. Nevertheless, glucose or its metabolism exerts a plethora of activating effects on many cellular functions. It is not clear, in which way glucose repression and induction are functionally linked.Glucose repression mechanisms in S. cerevisiae have been revealed by means of appropriate mutants either defective in repression or in derepression (for review, see [4]). Analysis of individual mutants allowed in some cases the identification or localization of the regulatory defect. A number of such mutants lead to the identification of transcription factors or transcriptional regulators of glucose-sensitive genes. There are a number of mutants which apparently affect functions early in the signalling pathway for glucoseCorrespondence to

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Section: Discussionmentioning

confidence: 99%

Glucose Uptake and Metabolism in grr1/cat80 Mutants of Sacharomyces cerevisiae

Özcan

Schulte

Freidel

et al. 1994

European Journal of Biochemistry

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“…The S. cerevisiae hexose transporters solely mediate facilitated diffusion of their substrates down a concentration gradient (Lagunas, 1993). In contrast, several other yeasts, plant cells and bacterial cells can actively transport hexoses and pentoses by proton-symport mechanisms against concentration gradients (Boles & Hollenberg, 1997 ;Bu$ ttner & Sauer, 2000).…”

Section: Expression Of Heterologous Monosaccharide Transporters In Smentioning

confidence: 99%

Characterization of the xylose-transporting properties of yeast hexose transporters and their influence on xylose utilization

et al. 2002

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For an economically feasible production of ethanol from plant biomass by microbial cells, the fermentation of xylose is important. As xylose uptake might be a limiting step for xylose fermentation by recombinant xyloseutilizing Saccharomyces cerevisiae cells a study of xylose uptake was performed. After deletion of all of the 18 hexose-transporter genes, the ability of the cells to take up and to grow on xylose was lost. Reintroduction of individual hexose-transporter genes in this strain revealed that at intermediate xylose concentrations the yeast high-and intermediate-affinity transporters Hxt4, Hxt5, Hxt7 and Gal2 are important xylose-transporting proteins. Several heterologous monosaccharide transporters from bacteria and plant cells did not confer sufficient uptake activity to restore growth on xylose. Overexpression of the xylose-transporting proteins in a xylose-utilizing PUA yeast strain did not result in faster growth on xylose under aerobic conditions nor did it enhance the xylose fermentation rate under anaerobic conditions. The results of this study suggest that xylose uptake does not determine the xylose flux under the conditions and in the yeast strains investigated.

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“…This fraction principally consists of the fermentable sugars glucose, fructose, maltose and maltotriose. Typically, these sugars are utilized sequentially by yeast cells, with sucrose (which occurs only in low concentrations) depleted first, followed by the monosaccharides glucose and fructose (Lagunas, 1993). Maltose and maltotriose, which are the most abundant sugars, will typically only be taken up after depletion of the monosaccharides, due to carbon catabolite repression of metabolic pathways involved in the uptake and utilization of alternative sugars (Lagunas, 1993).…”

Section: Introductionmentioning

confidence: 99%

Carbohydrate utilization and the lager yeast transcriptome during brewery fermentation

Gibson

Boulton

Box

et al. 2008

Yeast

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The fermentable carbohydrate composition of wort and the manner in which it is utilized by yeast during brewery fermentation have a direct influence on fermentation efficiency and quality of the final product. In this study the response of a brewing yeast strain to changes in wort fermentable carbohydrate concentration and composition during full-scale (3275 hl) brewery fermentation was investigated by measuring transcriptome changes with the aid of oligonucleotide-based DNA arrays. Up to 74% of the detectable genes showed a significant (p ≤ 0.01) differential expression pattern during fermentation and the majority of these genes showed transient or prolonged peaks in expression following the exhaustion of the monosaccharides from the wort. Transcriptional activity of many genes was consistent with their known responses to glucose de/repression under laboratory conditions, despite the presence of di-and trisaccharide sugars in the wort. In a number of cases the transcriptional response of genes was not consistent with their known responses to glucose, suggesting a degree of complexity during brewery fermentation which cannot be replicated in small-scale wort fermentations or in laboratory experiments involving defined media.

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Sugar transport in Saccharomyces cerevisiae

Cited by 124 publications

References 134 publications

Glucose Uptake and Metabolism in grr1/cat80 Mutants of Sacharomyces cerevisiae

Glucose Uptake and Metabolism in grr1/cat80 Mutants of Sacharomyces cerevisiae

Characterization of the xylose-transporting properties of yeast hexose transporters and their influence on xylose utilization

Carbohydrate utilization and the lager yeast transcriptome during brewery fermentation

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