Impaired control of IRES-mediated translation in X-linked dyskeratosis congenita

Science. 2006 May 12;312(5775):902-6. doi: 10.1126/science.1123835.

Abstract

The DKC1 gene encodes a pseudouridine synthase that modifies ribosomal RNA (rRNA). DKC1 is mutated in people with X-linked dyskeratosis congenita (X-DC), a disease characterized by bone marrow failure, skin abnormalities, and increased susceptibility to cancer. How alterations in ribosome modification might lead to cancer and other features of the disease remains unknown. Using an unbiased proteomics strategy, we discovered a specific defect in IRES (internal ribosome entry site)-dependent translation in Dkc1(m) mice and in cells from X-DC patients. This defect results in impaired translation of messenger RNAs containing IRES elements, including those encoding the tumor suppressor p27(Kip1) and the antiapoptotic factors Bcl-xL and XIAP (X-linked Inhibitor of Apoptosis Protein). Moreover, Dkc1(m) ribosomes were unable to direct translation from IRES elements present in viral messenger RNAs. These findings reveal a potential mechanism by which defective ribosome activity leads to disease and cancer.

MeSH terms

  • 5' Untranslated Regions*
  • Animals
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / genetics*
  • Cell Cycle Proteins / physiology
  • Cell Line
  • Cells, Cultured
  • Cyclin-Dependent Kinase Inhibitor p27 / biosynthesis
  • Cyclin-Dependent Kinase Inhibitor p27 / genetics
  • Dyskeratosis Congenita / genetics*
  • Humans
  • Insect Viruses / genetics
  • Lymphocytes / metabolism
  • Male
  • Mice
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / physiology
  • Oligonucleotide Array Sequence Analysis
  • Point Mutation
  • Polyribosomes / metabolism
  • Protein Biosynthesis*
  • Proteomics
  • Pseudouridine / metabolism
  • RNA Viruses / genetics
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism
  • RNA, Ribosomal / metabolism
  • Transfection
  • X-Linked Inhibitor of Apoptosis Protein / biosynthesis
  • X-Linked Inhibitor of Apoptosis Protein / genetics
  • bcl-X Protein / biosynthesis
  • bcl-X Protein / genetics

Substances

  • 5' Untranslated Regions
  • Cell Cycle Proteins
  • DKC1 protein, human
  • Dkc1 protein, mouse
  • Nuclear Proteins
  • RNA, Messenger
  • RNA, Ribosomal
  • X-Linked Inhibitor of Apoptosis Protein
  • bcl-X Protein
  • Pseudouridine
  • Cyclin-Dependent Kinase Inhibitor p27