ALS Mutations in FUS Cause Neuronal Dysfunction and Death in Caenorhabditis Elegans by a Dominant Gain-Of-Function Mechanism

Hum Mol Genet. 2012 Jan 1;21(1):1-9. doi: 10.1093/hmg/ddr417. Epub 2011 Sep 23.

Abstract

It is unclear whether mutations in fused in sarcoma (FUS) cause familial amyotrophic lateral sclerosis via a loss-of-function effect due to titrating FUS from the nucleus or a gain-of-function effect from cytoplasmic overabundance. To investigate this question, we generated a series of independent Caenorhabditis elegans lines expressing mutant or wild-type (WT) human FUS. We show that mutant FUS, but not WT-FUS, causes cytoplasmic mislocalization associated with progressive motor dysfunction and reduced lifespan. The severity of the mutant phenotype in C. elegans was directly correlated with the severity of the illness caused by the same mutation in humans, arguing that this model closely replicates key features of the human illness. Importantly, the mutant phenotype could not be rescued by overexpression of WT-FUS, even though WT-FUS had physiological intracellular localization, and was not recruited to the cytoplasmic mutant FUS aggregates. Our data suggest that FUS mutants cause neuronal dysfunction by a dominant gain-of-function effect related either to neurotoxic aggregates of mutant FUS in the cytoplasm or to dysfunction in its RNA-binding functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyotrophic Lateral Sclerosis / genetics
  • Amyotrophic Lateral Sclerosis / metabolism*
  • Amyotrophic Lateral Sclerosis / physiopathology
  • Animals
  • Animals, Genetically Modified
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism*
  • Cell Death
  • Disease Models, Animal
  • Female
  • Humans
  • Male
  • Motor Neurons / cytology*
  • Motor Neurons / metabolism
  • Mutation*
  • RNA-Binding Protein FUS / genetics*
  • RNA-Binding Protein FUS / metabolism*

Substances

  • RNA-Binding Protein FUS