Effect of xylose incubation on the glucose transport system in Saccharomyces cerevisiae.
Incubation of Saccharomyces cerevisiae with xylose and ethanol for 16 hours leads to a decrease of hexokinase (and glucokinase) activity in the cells. It does not alter the levels of polyphosphate, orthophosphate and ATP. The transport of the glucose derivative 2-deoxy-D-glucose, a sugar that can be phosphorylated, is inhibited after this treatment, whereas transport of 6-deoxy-D-glucose, which has a blocked phosphorylation site, is not inhibited. Even though, both deoxyglucoses use the same transport system. The decrease in initial velocity of 2-deoxy-D-glucose transport is most pronounced under anaerobic conditions. Incubation of the cells with antimycin A, a treatment which has a similar effect as anaerobiosis, shows, that the inhibition of the transport of 2-deoxy-D-glucose is presumably the result of an increase in the Km of the carrier transport. Transport of glucose is probably regulated by kinase enzymes.
D001692:Biological Transport / Q000187:drug effects; D003847:Deoxyglucose / Q000378:metabolism; D005941:Glucokinase / Q000037:antagonists & inhibitors; D005947:Glucose / Q000378:metabolism*; D006593:Hexokinase / Q000037:antagonists & inhibitors; D007700:Kinetics; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D014994:Xylose / Q000494:pharmacology*
D003847:Deoxyglucose; D014994:Xylose; D006593:Hexokinase; D005941:Glucokinase; D005947:Glucose