Recessive nonsense-suppression in yeast: involvement of 60S ribosomal subunit.

The ribosomal protein patterns of recessive suppressor strain and parent strain of Saccharomyces cerevisiae were analyzed by two-dimensional polyacrylamide gel electrophoresis. About 30 proteinspots were found for ribosomal proteins of small subunit for both mutant and parent strain. These patterns do not differ from each other neither in intensity of staining, nor in mobility of spots. 41 protein spots were found in electrophoregrams of 60S ribosomal proteins both from parent strain and recessive suppressor strain. The electrophoretic picture of the 60S proteins from the parent and mutant strains is similar except the intensity of staining of the L30 spot. This protein is present in 60S subunit of suppressor strain and completely absent or only weakly stained on electrophoregrams of ribosomal proteins of parent strain. The possible relationships between the content of L30 protein and the mechanism of recessive suppression in yeast are discussed.