Timing and Variability of Galactose Metabolic Gene Activation Depend on the Rate of Environmental Change.

ABSTRACT: Modulation of gene network activity allows cells to respond to changes in environmental conditions. For example, the galactose utilization network in Saccharomyces cerevisiae is activated by the presence of galactose but repressed by glucose. If both sugars are present, the yeast will first metabolize glucose, depleting it from the extracellular environment. Upon depletion of glucose, the genes encoding galactose metabolic proteins will activate. Here, we show that the rate at which glucose levels are depleted determines the timing and variability of galactose gene activation. Paradoxically, we find that Gal1p, an enzyme needed for galactose metabolism, accumulates more quickly if glucose is depleted slowly rather than taken away quickly. Furthermore, the variability of induction times in

SUBMITTER: Nguyen-Huu TD 

PROVIDER: S-EPMC4511807 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature