SEARCH

SEARCH BY CITATION

Keywords:

  • amyotrophic lateral sclerosis;
  • ER-Golgi transport;
  • neurodegeneration

Abstract

Thumbnail image of graphical abstract

Cu/Zn-superoxide dismutase is misfolded in familial and sporadic amyotrophic lateral sclerosis, but it is not clear how this triggers endoplasmic reticulum (ER) stress or other pathogenic processes. Here, we demonstrate that mutant SOD1 (mSOD1) is predominantly found in the cytoplasm in neuronal cells. Furthermore, we show that mSOD1 inhibits secretory protein transport from the ER to Golgi apparatus. ER-Golgi transport is linked to ER stress, Golgi fragmentation and axonal transport and we also show that inhibition of ER-Golgi trafficking preceded ER stress, Golgi fragmentation, protein aggregation and apoptosis in cells expressing mSOD1. Restoration of ER-Golgi transport by over-expression of coatomer coat protein II subunit Sar1 protected against inclusion formation and apoptosis, thus linking dysfunction in ER-Golgi transport to cellular pathology. These findings thus link several cellular events in amyotrophic lateral sclerosis into a single mechanism occurring early in mSOD1 expressing cells.

Cu/Zn-superoxide dismutase (SOD1) is misfolded in familial and sporadic Amyotrophic Lateral Sclerosis, but it is unclear how this triggers endoplasmic reticulum (ER) stress and other cellular events. Here, we show that mutant SOD1 inhibits protein transport from the ER to Golgi apparatus prior to ER stress, Golgi fragmentation and apoptosis, and restoration of transport prevents inclusion formation and apoptosis. COPII: coatomer coat protein II.