Factors influencing the observed half-lives of specific synthetic capacities in Saccharomyces cerevisiae.

We have identified a variety of factors affecting the stability of allophanate hydrolase-specific and gross cellular protein synthetic capacities. These synthetic capacities have been extrapolated by many laboratories to represent functional messenger RNAs. Synthetic capacity turnover rates that we measured were greater in diploid organisms than in haploid strains and were proportional to the temperature of the culture medium. The stability of allophanate hydrolase-specific synthetic capacity was not influenced by alterations in the nitrogen source provided in the culture medium, but was increased up to 15-fold by the total inhibition of protein synthesis. Cultures in which protein synthesis was inhibited as little as 20% exhibited hydrolase-specific synthetic capacities more than 2-fold greater than those observed in the absence of inhibition.