Saccharomyces cerevisiae ribosomal protein L26 is not essential for ribosome assembly and function

Mol Cell Biol. 2012 Aug;32(16):3228-41. doi: 10.1128/MCB.00539-12. Epub 2012 Jun 11.

Abstract

Ribosomal proteins play important roles in ribosome biogenesis and function. Here, we study the evolutionarily conserved L26 in Saccharomyces cerevisiae, which assembles into pre-60S ribosomal particles in the nucle(ol)us. Yeast L26 is one of the many ribosomal proteins encoded by two functional genes. We have disrupted both genes; surprisingly, the growth of the resulting rpl26 null mutant is apparently identical to that of the isogenic wild-type strain. The absence of L26 minimally alters 60S ribosomal subunit biogenesis. Polysome analysis revealed the appearance of half-mers. Analysis of pre-rRNA processing indicated that L26 is mainly required to optimize 27S pre-rRNA maturation, without which the release of pre-60S particles from the nucle(ol)us is partially impaired. Ribosomes lacking L26 exhibit differential reactivity to dimethylsulfate in domain I of 25S/5.8S rRNAs but apparently are able to support translation in vivo with wild-type accuracy. The bacterial homologue of yeast L26, L24, is a primary rRNA binding protein required for 50S ribosomal subunit assembly in vitro and in vivo. Our results underscore potential differences between prokaryotic and eukaryotic ribosome assembly. We discuss the reasons why yeast L26 plays such an apparently nonessential role in the cell.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Base Sequence
  • Cell Nucleolus / metabolism
  • Crystallization
  • Evolution, Molecular
  • Green Fluorescent Proteins / metabolism
  • Microscopy, Fluorescence / methods
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation
  • Nucleic Acid Conformation
  • Plasmids / metabolism
  • Polyribosomes / chemistry
  • Protein Conformation
  • RNA / metabolism
  • Reproducibility of Results
  • Ribosomal Proteins / genetics
  • Ribosomal Proteins / physiology*
  • Ribosomes / metabolism*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / physiology*
  • Software

Substances

  • RPL26A protein, S cerevisiae
  • RPL26B protein, S cerevisiae
  • Ribosomal Proteins
  • Saccharomyces cerevisiae Proteins
  • Green Fluorescent Proteins
  • RNA