FUS regulates RAN translation through modulating the G-quadruplex structure of GGGGCC repeat RNA in C9orf72-linked ALS/FTD

Elife. 2023 Jul 18:12:RP84338. doi: 10.7554/eLife.84338.

Abstract

Abnormal expansions of GGGGCC repeat sequence in the noncoding region of the C9orf72 gene is the most common cause of familial amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD). The expanded repeat sequence is translated into dipeptide repeat proteins (DPRs) by noncanonical repeat-associated non-AUG (RAN) translation. Since DPRs play central roles in the pathogenesis of C9-ALS/FTD, we here investigate the regulatory mechanisms of RAN translation, focusing on the effects of RNA-binding proteins (RBPs) targeting GGGGCC repeat RNAs. Using C9-ALS/FTD model flies, we demonstrated that the ALS/FTD-linked RBP FUS suppresses RAN translation and neurodegeneration in an RNA-binding activity-dependent manner. Moreover, we found that FUS directly binds to and modulates the G-quadruplex structure of GGGGCC repeat RNA as an RNA chaperone, resulting in the suppression of RAN translation in vitro. These results reveal a previously unrecognized regulatory mechanism of RAN translation by G-quadruplex-targeting RBPs, providing therapeutic insights for C9-ALS/FTD and other repeat expansion diseases.

Keywords: ALS; C9orf72; D. melanogaster; FUS; RAN translation; RNA chaperone; neuroscience; repeat expansion disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyotrophic Lateral Sclerosis* / pathology
  • C9orf72 Protein / genetics
  • C9orf72 Protein / metabolism
  • Drosophila / genetics
  • Frontotemporal Dementia* / pathology
  • Humans
  • RNA / metabolism
  • RNA-Binding Protein FUS / genetics
  • RNA-Binding Proteins / genetics

Substances

  • C9orf72 Protein
  • C9orf72 protein, human
  • FUS protein, human
  • RNA
  • RNA-Binding Protein FUS
  • RNA-Binding Proteins

Grants and funding

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.