Dependence of ribonucleic acid synthesis on continuous protein synthesis in yeast.

Using an auxotrophic strain of Saccharomyces cerevisiae, we examined the kinetics of ribonucleic acid (RNA) synthesis following inhibition of protein synthesis caused by amino acid starvation or cycloheximide. Removal of a required amino acid immediately stopped net protein synthesis. After a brief lag, RNA synthesis also ceased. Cycloheximide, a ribosome-inhibiting drug, also immediately halted net protein synthesis. Again RNA synthesis stopped after a brief lag. Although cycloheximide and amino acid starvation affect different steps in protein biosynthesis, both inhibited RNA synthesis in identical fashion. This indicates that amino acids do not play a unique role in the control of RNA production in rapidly growing yeast; rather, it suggests that RNA synthesis is responsive to the overall rate of protein synthesis itself.