The influence of ATP on sugar uptake mediated by the constitutive glucose carrier of Saccharomyces cerevisiae.
The glucose carrier of Saccharomyces cerevisiae transports the phosphorylatable sugars glucose, mannose, fructose and 2-deoxy-D-glucose (2-dGlc) and the non-phosphorylatable sugar 6-deoxy-D-glucose (6-dGlc). Reduction of the ATP concentration by, for example, incubating cells with antimycin A, results in a decrease in uptake of 2-dGlc and fructose. These uptake velocities can be increased again by raising the ATP level. These results establish a role of ATP in sugar transport. Transport of glucose and mannose is less affected by changes in the ATP concentration than 2-dGlc and fructose uptake, while the 6-dGlc transport is independent of the amount of ATP in the cells. Also, reduction of the kinase activity by incubation with xylose diminished transport of 2-dGlc and fructose, while the uptake of glucose and mannose remained unchanged. It is discussed that these results are due to transport-associated phosphorylation with ATP as substrate and the hexokinases and the glucokinase as phosphorylating enzymes.
Schuddemat
J
J
Department of Medical Biochemistry, Sylvius Laboratoria, Leiden, The Netherlands.
van den Broek
P J
PJ
van Steveninck
J
J
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D050260:Carbohydrate Metabolism; D003847:Deoxyglucose / Q000378:metabolism; D005632:Fructose / Q000378:metabolism; D008358:Mannose / Q000378:metabolism; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*
D009004:Monosaccharide Transport Proteins; D005632:Fructose; D000255:Adenosine Triphosphate; D003847:Deoxyglucose; D008358:Mannose