rRNA Pseudouridylation Defects Affect Ribosomal Ligand Binding and Translational Fidelity From Yeast to Human Cells

Mol Cell. 2011 Nov 18;44(4):660-6. doi: 10.1016/j.molcel.2011.09.017.

Abstract

How pseudouridylation (Ψ), the most common and evolutionarily conserved modification of rRNA, regulates ribosome activity is poorly understood. Medically, Ψ is important because the rRNA Ψ synthase, DKC1, is mutated in X-linked dyskeratosis congenita (X-DC) and Hoyeraal-Hreidarsson (HH) syndrome. Here, we characterize ribosomes isolated from a yeast strain in which Cbf5p, the yeast homolog of DKC1, is catalytically impaired through a D95A mutation (cbf5-D95A). Ribosomes from cbf5-D95A cells display decreased affinities for tRNA binding to the A and P sites as well as the cricket paralysis virus internal ribosome entry site (IRES), which interacts with both the P and the E sites of the ribosome. This biochemical impairment in ribosome activity manifests as decreased translational fidelity and IRES-dependent translational initiation, which are also evident in mouse and human cells deficient for DKC1 activity. These findings uncover specific roles for Ψ modification in ribosome-ligand interactions that are conserved in yeast, mouse, and humans.

Publication types

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

MeSH terms

  • Animals
  • Binding Sites
  • Cell Cycle Proteins / deficiency*
  • Cell Cycle Proteins / genetics
  • Dyskeratosis Congenita / enzymology
  • Dyskeratosis Congenita / genetics*
  • Fetal Growth Retardation / enzymology
  • Fetal Growth Retardation / genetics*
  • Genes, Reporter
  • Humans
  • Hydro-Lyases / deficiency*
  • Hydro-Lyases / genetics
  • Hydro-Lyases / metabolism*
  • Intellectual Disability / enzymology
  • Intellectual Disability / genetics*
  • Luciferases / analysis
  • Mice
  • Microcephaly / enzymology
  • Microcephaly / genetics*
  • Microtubule-Associated Proteins / deficiency*
  • Microtubule-Associated Proteins / genetics
  • Mutation
  • Nuclear Proteins / deficiency*
  • Nuclear Proteins / genetics
  • Plasmids
  • Protein Biosynthesis
  • RNA, Ribosomal / chemistry
  • RNA, Ribosomal / genetics
  • RNA, Ribosomal / metabolism*
  • RNA, Transfer / chemistry
  • RNA, Transfer / genetics
  • RNA, Transfer / metabolism*
  • Ribonucleoproteins, Small Nuclear / deficiency*
  • Ribonucleoproteins, Small Nuclear / genetics
  • Ribosomes / chemistry
  • Ribosomes / metabolism
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins / genetics
  • Sequence Homology, Amino Acid
  • Transduction, Genetic

Substances

  • Cell Cycle Proteins
  • DKC1 protein, human
  • Microtubule-Associated Proteins
  • Nuclear Proteins
  • RNA, Ribosomal
  • Ribonucleoproteins, Small Nuclear
  • Saccharomyces cerevisiae Proteins
  • RNA, Transfer
  • Luciferases
  • Hydro-Lyases
  • CBF5 protein, S cerevisiae
  • pseudouridylate synthetase

Supplementary concepts

  • Hoyeraal Hreidarsson syndrome