Expanded CUG Repeats Trigger Aberrant Splicing of ClC-1 Chloride Channel Pre-mRNA and Hyperexcitability of Skeletal Muscle in Myotonic Dystrophy

• Ami Mankodi ^[1] ; Masanori P. Takahashi ^[2] ; Hong Jiang ^[1] ; William J. Bowers ^[1] ; Richard T. Moxley ^[1]
  1. [1] University of Rochester

     University of Rochester

     City of Rochester, Estados Unidos

     
  2. [2] Harvard Medical School

     Harvard Medical School

     City of Boston, Estados Unidos

     
• Localización: Molecular cell, ISSN 1097-2765, Vol. 10, Nº 1, 2002, págs. 35-44
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • In myotonic dystrophy (dystrophia myotonica, DM), expression of RNAs that contain expanded CUG or CCUG repeats is associated with degeneration and repetitive action potentials (myotonia) in skeletal muscle. Using skeletal muscle from a transgenic mouse model of DM, we show that expression of expanded CUG repeats reduces the transmembrane chloride conductance to levels well below those expected to cause myotonia. The expanded CUG repeats trigger aberrant splicing of pre-mRNA for ClC-1, the main chloride channel in muscle, resulting in loss of ClC-1 protein from the surface membrane. We also have identified a similar defect in ClC-1 splicing and expression in two types of human DM. We propose that a transdominant effect of mutant RNA on RNA processing leads to chloride channelopathy and membrane hyperexcitability in DM.