AROUND THE GROWTH-PHASE TRANSITION S-CEREVISIAES MAKE-UP FAVORS SUSTAINED OSCILLATIONS OF INTRACELLULAR METABOLITES

Under a limited set of hitherto incompletely defined conditions, inhibition of respiration has been shown to cause transient oscillations in NAD(P)H fluorescence of yeast cells. In this paper, we apply a new method [1992, Anal. Biochem. 204, 118-1321 for extraction of intracellular metabolites. This method involves spraying the cells into -40-degrees-C methanol; the neutral pH allows extraction of nearly all intracellular metabolites, including NADH. Close to the shift from glucose to ethanol as a growth substrate, the cells acquire a make-up amenable to sustained oscillations in intracellular concentrations of NADH and glycolytic intermediates such as glucose-6-phosphate. NADH was found to oscillate between 200 muM and 400 muM intracellular concentration. The cellular make-up determining the tendency to oscillate is 'remembered' by the cells after three hours of starvation.