Synthesis of ribosomal proteins in developingDictyostelium discoideumcells is controlled by the methylation of proteins S24 and S31

Abstract

Ribosomal protein mRNAs left over from growth are selectively excluded from polyribosomes in the first half of Dictyostelium discoideum development. This is due to the fact that they are sequestered by a class of free 40S ribosomal subunits, characterized by possessing a methylated S24 protein. At the time of formation of tight cell aggregates, the methylated S24 is substituted by an unmethylated S24, while protein S31 of the same or other 40S subunits becomes methylated. This leads to a rapid degradation of the ribosomal protein mRNAs.Key words: synthesis of ribosomal proteins, Dictyostelium, methylation of S24, methylation of S31.