Modulation of sporulation and metabolic fluxes in Saccharomyces cerevisiae by 2 deoxy glucose.

Abstract

Quantitative studies of metabolic fluxes during Saccharomyces cerevisiae sporulation on acetate in the presence of the glucose analog, 2-deoxy glucose (2dG) are reported. We have studied the inhibition of sporulation and associated catabolic or anabolic fluxes by 2dG. Sporulation frequencies decreased from 50% to 2% asci per cell at 2dG concentrations in the range of 0.03 to 0.30 g l-1, respectively. Under the same conditions, the acetate consumption flux was inhibited up to 60% and the glyoxylate cycle and gluconeogenic fluxes decreased from 0.7 and 0.3 mmol h-1 g-1 dw, respectively, to negligible values. We observed a linear correlation of the acetate consumption rate with the sporulation frequency by varying the 2dG concentration. The linear correlation was also verified between the frequency of sporulation and the fluxes through glyoxylate cycle and gluconeogenic pathways. In addition, the same association of inhibition of sporulation and metabolic fluxes was found in other S. cerevisiae strains displaying different potentials of sporulation. The results presented suggest that inhibition of sporulation in the presence of the glucose analog may be attributed, at least in part, to the inhibition of anabolic fluxes and might be associated with catabolite repression.