Differential Translational Efficiency of the mRNAs Isolated from Derepressed and Glucose Repressed Saccharomyces cerevisiae

Summary: Carbon catabolite derepression induced changes in the pool of yeast mRNAs translatable in a protein-synthesizing reticulocyte system. Competition experiments with globin mRNA showed that the mRNA population obtained from derepressed cells possessed a higher translational efficiency than mRNA from repressed cells. The mRNAs that could account for the high translational efficiency of the derepressed mRNA were not detected in cells growing in glucose-rich medium. Analysis of protein synthesis in the presence of 7-methylguanosine 5′-phosphate indicated that the initiation factors recognizing the 5′-terminal structure of capped messengers interacted with lower affinity with the repressed than with some specific derepressed mRNAs.