Loss of glutathione redox homeostasis impairs proteostasis by inhibiting autophagy-dependent protein degradation

Cell Death Differ. 2019 Sep;26(9):1545-1565. doi: 10.1038/s41418-018-0270-9. Epub 2019 Feb 15.

Abstract

In the presence of aggregation-prone proteins, the cytosol and endoplasmic reticulum (ER) undergo a dramatic shift in their respective redox status, with the cytosol becoming more oxidized and the ER more reducing. However, whether and how changes in the cellular redox status may affect protein aggregation is unknown. Here, we show that C. elegans loss-of-function mutants for the glutathione reductase gsr-1 gene enhance the deleterious phenotypes of heterologous human, as well as endogenous worm aggregation-prone proteins. These effects are phenocopied by the GSH-depleting agent diethyl maleate. Additionally, gsr-1 mutants abolish the nuclear translocation of HLH-30/TFEB transcription factor, a key inducer of autophagy, and strongly impair the degradation of the autophagy substrate p62/SQST-1::GFP, revealing glutathione reductase may have a role in the clearance of protein aggregates by autophagy. Blocking autophagy in gsr-1 worms expressing aggregation-prone proteins results in strong synthetic developmental phenotypes and lethality, supporting the physiological importance of glutathione reductase in the regulation of misfolded protein clearance. Furthermore, impairing redox homeostasis in both yeast and mammalian cells induces toxicity phenotypes associated with protein aggregation. Together, our data reveal that glutathione redox homeostasis may be central to proteostasis maintenance through autophagy regulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid beta-Peptides / genetics
  • Amyloid beta-Peptides / metabolism
  • Animals
  • Autophagy / genetics*
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / growth & development
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism
  • Cell Line
  • Endoplasmic Reticulum / metabolism
  • Glutathione / genetics
  • Glutathione / metabolism*
  • Glutathione Reductase / genetics
  • Glutathione Reductase / metabolism*
  • Homeostasis / drug effects
  • Homeostasis / genetics
  • Humans
  • Maleates / pharmacology
  • Muscle Cells / metabolism
  • Neurons / metabolism
  • Oxidation-Reduction / drug effects
  • Peptides / antagonists & inhibitors
  • Peptides / toxicity*
  • Phenotype
  • Protein Aggregation, Pathological / metabolism*
  • Proteolysis / drug effects
  • Proteostasis / genetics*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Sequestosome-1 Protein / genetics
  • Sequestosome-1 Protein / metabolism
  • alpha-Synuclein / genetics
  • alpha-Synuclein / metabolism

Substances

  • Amyloid beta-Peptides
  • Basic Helix-Loop-Helix Transcription Factors
  • Caenorhabditis elegans Proteins
  • HLH-30 protein, C elegans
  • Maleates
  • Peptides
  • Sequestosome-1 Protein
  • alpha-Synuclein
  • polyglutamine
  • Glutathione Reductase
  • diethyl maleate
  • Glutathione