The response of diphosphoinositide and triphosphoinositide to perturbations of the adenylate energy charge in cells of Saccharomyces cerevisiae

Abstract

In cells of Saccharomyces cerevisiae uniformly labeled with 32P the levels of ATP, ADP, AMP, diphosphoinositide and triphosphoinositide were measured simultaneously after chromatographic separation. When a respiratory deficient mutant strain was removed from complete growth medium, there resulted an immediate and large drop in the levels of diphosphoinositide, triphosphoinositide, and ATP as well as the adenylate energy charge. Addition of glucose to starved cells in buffer resulted in a rapid increase in the concentrations of ATP, diphosphoinositide and triphosphoinositide. 2-Deoxyglucose caused a rapid decrease of the adenylate energy charge to intermediate values; again, the levels of diphosphoinositide and triphosphoinositide fell rapidly but not to the same extent as with simple starvation. The close association between the adenylate energy charge and the concentration of these polyphosphoinositides herein demonstrated is discussed in relation to the well known turnover of phosphomonoester groups of these lipids.