Description
Many studies in yeast have observed correlations between changes in phosphorylated adenosine and guanosine nucleotide concentrations, and changes in cell physiology or gene expression. Evidence for a causal relationship is however sparse. To investigate this further under controlled conditions, we have developed strains of S. cerevisiae containing inducible pathways which increase use of ATP or GTP. Analysis of the transcriptional response following induction of these strains during continuous culture in chemostats allowed the effects of specifically increasing the demand for each purine nucleotide triphosphate to be determined independently of growth rate and nutritional changes.