The Role of RpS9 in Ribosome Assembly and rRNA Processing in Saccharomyces cerevisiae

Abstract

RpS9, which is encoded by the gene RPS9, is one of 33 ribosomal proteins in the small subunit of the yeast ribosome. Previous studies have shown that ribosome biogenesis is severely inhibited when individual ribosomal proteins (r-proteins) on either the large or small subunit are depleted. However, the characterization of the exact roles of the different r-proteins in rRNA processing and ribosome assembly remains incomplete. This study shows through northern blot analysis and methylene blue staining of total RNA transferred to membranes that the depletion of RpS9 in the yeast Saccharomycescerevisiae (S. cerevisiae) leads to a buildup of rRNA precursors as well as a loss of mature 18S rRNA. Additionally, sucrose gradient profiling and growth curve characterization show that RpS9 depletion leads to a loss of small subunit formation and a decrease in growth rate.