Senataxin, the yeast Sen1p orthologue: characterization of a unique protein in which recessive mutations cause ataxia and dominant mutations cause motor neuron disease

Neurobiol Dis. 2006 Jul;23(1):97-108. doi: 10.1016/j.nbd.2006.02.007. Epub 2006 Apr 27.


A severe recessive cerebellar ataxia, Ataxia-Oculomotor Apraxia 2 (AOA2) and a juvenile onset form of dominant amyotrophic lateral sclerosis (ALS4) result from mutations of the Senataxin (SETX) gene. To begin characterization this disease protein, we developed a specific antibody to the DNA/RNA helicase domain of SETX. In murine brain, SETX concentrates in several regions, including cerebellum, hippocampus and olfactory bulb with a general neuronal expression profile, colocalizing with NeuN. In cultured cells, we found that SETX was cytoplasmically diffuse, but in the nucleus, SETX was punctate, colocalizing with fibrillarin, a marker of the nucleolus. In differentiated non-cycling cells, nuclear SETX was not restricted to the nucleolus but was diffuse within the nucleoplasm, suggesting cell-cycle-dependent localization. SETX missense mutations cluster within the N-terminus and helicase domains. Flag tagging at the N-terminus caused protein mislocation to the nucleoplasm and failure to export to the cytoplasm, suggesting that the N-terminus may be essential for correct SETX localization. We report here the first characterization of SETX protein, which may provide future insights into a new mechanism leading to neuron death.

Publication types

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

MeSH terms

  • Adult
  • Animals
  • Ataxia / metabolism*
  • Blotting, Western
  • COS Cells
  • Chlorocebus aethiops
  • Electrophoresis, Polyacrylamide Gel
  • Female
  • Fluorescent Antibody Technique
  • HeLa Cells
  • Humans
  • Motor Neuron Disease / metabolism*
  • Mutation
  • RNA Helicases / physiology*


  • RNA Helicases