2. Academic Validation
  3. A novel nuclear DnaJ protein, DNAJC8, can suppress the formation of spinocerebellar ataxia 3 polyglutamine aggregation in a J-domain independent manner

A novel nuclear DnaJ protein, DNAJC8, can suppress the formation of spinocerebellar ataxia 3 polyglutamine aggregation in a J-domain independent manner

  • Biochem Biophys Res Commun. 2016 Jun 10;474(4):626-633. doi: 10.1016/j.bbrc.2016.03.152.
Norie Ito 1,  Kenjiro Kamiguchi 2,  Katsuya Nakanishi 2,  Alice Sokolovskya 2,  Yoshihiko Hirohashi 2,  Yasuaki Tamura 2,  Aiko Murai 2,  Eri Yamamoto 2,  Takayuki Kanaseki 2,  Tomohide Tsukahara 2,  Vitaly Kochin 2,  Susumu Chiba 3,  Shun Shimohama 4,  Noriyuki Sato 2,  Toshihiko Torigoe 5
Affiliations

Affiliations

  • 1 Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan; Department of Neurology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan.
  • 2 Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan.
  • 3 Department of Neurology, Clinical Brain Research Laboratory, Toyokura Memorial Hall, Sapporo Yamano-ue Hospital, Japan.
  • 4 Department of Neurology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan.
  • 5 Department of Pathology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060-8556, Japan. Electronic address: torigoe@sapmed.ac.jp.
PMID: 27133716 DOI: 10.1016/j.bbrc.2016.03.152
Abstract

Polyglutamine (polyQ) diseases comprise neurodegenerative disorders caused by expression of expanded polyQ-containing proteins. The cytotoxicity of the expanded polyQ-containing proteins is closely associated with aggregate formation. In this study, we report that a novel J-protein, DNAJ (HSP40) Homolog, Subfamily C, Member 8 (DNAJC8), suppresses the aggregation of polyQ-containing protein in a cellular model of spinocerebellar ataxia type 3 (SCA3), which is also known as Machado-Joseph disease. Overexpression of DNAJC8 in SH-SY5Y neuroblastoma cells significantly reduced the polyQ aggregation and Apoptosis, and DNAJC8 was co-localized with the polyQ aggregation in the cell nucleus. Deletion mutants of DNAJC8 revealed that the C-terminal domain of DNAJC8 was essential for the suppression of polyQ aggregation, whereas the J-domain was dispensable. Furthermore, 22-mer oligopeptide derived from C-termilal domain could suppress the polyQ aggregation. These results indicate that DNAJC8 can suppress the polyQ aggregation via a distinct mechanism independent of HSP70-based chaperone machinery and have a unique protective role against the aggregation of expanded polyQ-containing proteins such as pathogenic ataxin-3 proteins.

Keywords

Ataxin-3; DNAJC8; PolyQ disease; Spinocerebellar ataxia type 3.

Figures