Uptake and phosphorylation of 2-deoxy-D-glucose by wild-type and single-kinase strains of Saccharomyces cerevisiae.
The role of phosphorylation in sugar transport in baker's yeast was studied using 2-deoxy-D-glucose. In wild-type baker's yeast, 2-deoxy-D-glucose is accumulated as a mixture of the free sugar and several derivatives. Pool labeling experiments, designed to determine the temporal order of appearance of labeled 2-deoxy-D-glucose in the intracellular pools, have confirmed previous reports that 2-deoxy-D-glucose first appears in the sugar phosphate pool. Such results are consistent with a transport associated phosphorylation mechanism. Since wild-type yeasts contain three enzymes which could participate in such a process, hexokinase isozymes PI and PII and glucokinase, pool labeling experiments were carried out with single-kinase mutant strains containing only one of these enzymes. Results similar to those for wild-type strains were obtained for all three single-kinase strains, suggesting that if transport associated phosphorylation does occur in baker's yeast, it is not a function of the specific kinase present in the cell. While the results of the pool labeling experiments are consistent with a transport associated phosphorylation mechanism for 2-deoxy-D-glucose, caution is urged in interpreting the results of experiments with whole cells where problems of compartmentation and multiple pools are difficult to assess.
D001692:Biological Transport; D003837:Deoxy Sugars / Q000378:metabolism*; D003847:Deoxyglucose / Q000378:metabolism*; D005838:Genotype; D006593:Hexokinase / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D007700:Kinetics; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity
D003837:Deoxy Sugars; D007527:Isoenzymes; D003847:Deoxyglucose; D006593:Hexokinase