Growth phase dependence of invertase mRNA levels in yeast

Poly(A)-containing RNA from Saccharomyces cerevisiae was translated in the wheat germ protein-synthesizing system and yielded as one of its products a polypeptide which was identified as invertase. This characterization was based on the presence of a protein band at 60,000 daltons following immunoprecipitation with a specific invertase antibody, and the formation from this protein of staphylococcal V8 protease and cyanogen bromide peptides, which were similar in size to those from carbohydrate-depleted invertase. The observed increase in invertase activity from the early to mid logarithmic stage of cell growth was synchronous with the appearance of translatable invertase mRN in these cells. No translatable invertase mRNA, however, was detected in late logarithmic cells, although a constant level of invertase activity was present in the culture medium.