Polyglutamine-expanded ataxin-1 recruits Cu/Zn-superoxide dismutase into the nucleus of HeLa cells

Sung Jo Kim, Tae Soo Kim, Ick Young Kim, Sunghoi Hong, Hyangshuk Rhim, Seongman Kang

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Spinocerebellar ataxia 1 (SCA1) is an inherited neurodegenerative disorder caused by expansion of the polyglutamine stretch in ataxin-1, the SCA1 gene product. Polyglutamine expansion leads to the aggregation of ataxin-1 proteins. Superoxide dismutases (SODs) are involved in the pathogenesis of other aggregate-forming neurodegenerative diseases and are known to localize in the cytoplasm. Here, we show that Cu/Zn-SOD is translocated into the nucleus of HeLa cells in the presence of expanded ataxin-1, whereas Mn-SOD is localized in the cytoplasm: the longer the expansion of polyglutamine, the higher the level of translocation of Cu/Zn-SOD. In addition, the oxidation of intracellular proteins occurs with higher frequency in the presence of mutant ataxin-1 (82Q), suggesting that the functional activity of Cu/Zn-SOD might be decreased by mutant ataxin-1. We demonstrate that mutant ataxin-1-expressing cells encounter mitochondrial dysfunction in the conditions of oxidative stress. Our results suggest that polyglutamine-expanded ataxin-1 increases the levels of reactive oxygen species in HeLa cells.

Original languageEnglish
Pages (from-to)660-665
Number of pages6
JournalBiochemical and biophysical research communications
Issue number3
Publication statusPublished - 2003 Aug 1


  • Aggregate
  • Polyglutamine
  • Reactive oxygen species
  • SCA1
  • Superoxide dismutase

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology


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