Rps26 directs mRNA-specific translation by recognition of Kozak sequence elements

Nat Struct Mol Biol. 2017 Sep;24(9):700-707. doi: 10.1038/nsmb.3442. Epub 2017 Jul 31.

Abstract

We describe a novel approach to separate two ribosome populations from the same cells and use this method in combination with RNA-seq to identify mRNAs bound to Saccharomyces cerevisiae ribosomes with and without Rps26, a protein linked to the pathogenesis of Diamond-Blackfan anemia (DBA). These analyses reveal that Rps26 contributes to mRNA-specific translation by recognition of the Kozak sequence in well-translated mRNAs and that Rps26-deficient ribosomes preferentially translate mRNA from select stress-response pathways. Surprisingly, exposure of yeast to these stresses leads to the formation of Rps26-deficient ribosomes and to the increased translation of their target mRNAs. These results describe a novel paradigm: the production of specialized ribosomes, which play physiological roles in augmenting the well-characterized transcriptional stress response with a heretofore unknown translational response, thereby creating a feed-forward loop in gene expression. Moreover, the simultaneous gain-of-function and loss-of-function phenotypes from Rps26-deficient ribosomes can explain the pathogenesis of DBA.

MeSH terms

  • Protein Binding
  • Protein Biosynthesis*
  • RNA, Messenger / metabolism*
  • Ribosomal Proteins / metabolism*
  • Ribosomes / metabolism*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • RNA, Messenger
  • RPS26A protein, S cerevisiae
  • Ribosomal Proteins
  • Saccharomyces cerevisiae Proteins