Translation of HTT mRNA with expanded CAG repeats is regulated by the MID1-PP2A protein complex

Nat Commun. 2013:4:1511. doi: 10.1038/ncomms2514.

Abstract

Expansion of CAG repeats is a common feature of various neurodegenerative disorders, including Huntington's disease. Here we show that expanded CAG repeats bind to a translation regulatory protein complex containing MID1, protein phosphatase 2A and 40S ribosomal S6 kinase. Binding of the MID1-protein phosphatase 2A protein complex increases with CAG repeat size and stimulates translation of the CAG repeat expansion containing messenger RNA in a MID1-, protein phosphatase 2A- and mammalian target of rapamycin-dependent manner. Our data indicate that pathological CAG repeat expansions upregulate protein translation leading to an overproduction of aberrant protein and suggest that the MID1-complex may serve as a therapeutic target for the treatment of CAG repeat expansion disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • HeLa Cells
  • Humans
  • Huntingtin Protein
  • Luciferases / metabolism
  • Mice
  • Microtubule Proteins / metabolism*
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Nuclear Proteins / metabolism*
  • Nucleotide Motifs
  • Protein Binding
  • Protein Biosynthesis / genetics*
  • Protein Phosphatase 2 / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • TOR Serine-Threonine Kinases / metabolism
  • Transcription Factors / metabolism*
  • Trinucleotide Repeat Expansion / genetics*
  • Ubiquitin-Protein Ligases

Substances

  • HTT protein, human
  • Huntingtin Protein
  • Microtubule Proteins
  • Nerve Tissue Proteins
  • Nuclear Proteins
  • RNA, Messenger
  • Transcription Factors
  • Luciferases
  • MID1 protein, human
  • Ubiquitin-Protein Ligases
  • MTOR protein, human
  • TOR Serine-Threonine Kinases
  • Protein Phosphatase 2