ISSN:
0749-503X
Keywords:
Glucose-transport
;
rapid-kinetics
;
S. cerevisiae
;
Life and Medical Sciences
;
Genetics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Incubation of starved galactose-grown S. cerevisiae cells with cyanide reduced glucose uptake as measured over a 5-s period. The Vmax for glucose uptake was decreased by over a factor of two but the apparent affinity for glucose doubled. When measured in the sub-second time scale, however, there was no significant inhibition of glucose uptake, by cyanide, up to 200-ms, clearly demonstrating that, in cyanide treated cells, glucose uptake was not linear for the first 5-s.After a 200-ms exposure of untreated cells to radio-labelled glucose, less than 10% of the intracellular label resided in soluble uncharged compounds. In cyanide-treated cells up to 43% of the labelled compounds were uncharged, with a concurrent reduction of intracellular label residing in anionic compounds. The results suggest that, in the presence of 10 mM cyanide when respiration is inhibited, a reduction in the cellular ATP concentration causes a reduction in hexose-kinase activity which results in an accumulation of internal free glucose, which in turn causes a reduction in net glucose transport.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/yea.320101204
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