Phosphorylation of ribosomal proteins during differentiation of Saccharomyces cerevisiae.

Four major phosphoproteins of yeast ribosomes: S2, S6, L44 and L45, were identified in germinating spores. It was found that protein S6 became phosphorylated at an early stage of germination and that only the phosphorylation of this protein responded well to changes in growth conditions of yeast culture. The results obtained give support for the suggested functional role of modification of S6 protein.