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Updated: Feb 13, 2026

Examining Proteasome Assembly with Recombinant Archaeal Proteasomes and Nondenaturing PAGE: The Case for a Combined Approach
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Early cysteine-dependent inactivation of 26S proteasomes does not involve particle disassembly

Martín Hugo1, Ioanna Korovila1, Markus Köhler1

  • 1Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558 Nuthetal, Germany.

Redox Biology
|March 3, 2018
PubMed

Insights

Oxidative stress causes 26S proteasome disassembly, but moderate redox imbalance inhibits its activity before disassembly. This suggests a novel redox signaling pathway regulating proteasome function.

Area of Science:

  • Biochemistry
  • Cell Biology
  • Redox Biology

Background:

  • The 26S proteasome, a large protein complex, degrades ubiquitinated proteins.
  • Oxidative stress can lead to proteasome disassembly and altered function.
  • HSP70 mediates the reversible disassembly of 26S proteasomes into 20S and 19S subunits under oxidative stress.

Purpose of the Study:

  • To investigate the early effects of moderate redox imbalance on 26S proteasome activity.
  • To elucidate the mechanism of proteasome regulation under redox signaling conditions.

Main Methods:

  • Antimycin A stimulation to induce reactive oxygen species (ROS) production.
  • Monitoring peroxiredoxin dimerization and protein thiol oxidation.
  • Assessing ATP stimulation of 26S proteasome activity.
  • Investigating proteasome subunit disassembly.

Main Results:

  • Low ROS fluxes induced peroxiredoxin dimerization but not overoxidation.
  • Moderate redox imbalance inhibited ATP stimulation of 26S proteasome activity.
  • This inhibition was dependent on reversible cysteine oxidation and occurred before proteasome disassembly.
  • Identified an intermediate step in redox regulation of the 26S proteasome.

Conclusions:

  • The 26S proteasome is regulated by reversible cysteine oxidation during redox signaling.
  • An early inhibitory step precedes proteasome disassembly under moderate redox imbalance.
  • This finding highlights a novel mechanism of proteasome regulation relevant to redox signaling.

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