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Regulation of the 26S proteasome complex during oxidative stress

Xiaorong Wang1, James Yen, Peter Kaiser

  • 1Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA.

Science Signaling
|December 9, 2010
PubMed

Insights

Oxidative stress causes proteasome (26S proteasome) disassembly, impairing protein degradation. The protein Ecm29 is crucial for this process, aiding cellular recovery from hydrogen peroxide (H₂O₂) exposure.

Area of Science:

  • Cellular Biology
  • Biochemistry
  • Oxidative Stress Response

Background:

  • The proteasome is essential for protein homeostasis and cellular function.
  • Oxidative stress disrupts cellular processes, necessitating adaptive mechanisms.
  • Understanding proteasome dynamics under stress is key to cellular defense.

Purpose of the Study:

  • To investigate structural alterations in the 26S proteasome under oxidative stress.
  • To elucidate the role of proteasome-interacting proteins in stress response.
  • To determine the functional significance of proteasome subunit dissociation.

Main Methods:

  • Biochemical assays
  • Mass spectrometry
  • Yeast genetics (gene deletion)

Main Results:

  • Hydrogen peroxide (H₂O₂) induced dissociation of the 20S core particle from the 19S regulatory particle of the 26S proteasome.
  • This dissociation led to reduced proteasome activity and accumulation of ubiquitinated proteins.
  • Ecm29 protein facilitated H₂O₂-induced proteasome disassembly, and its absence increased sensitivity to oxidative stress.
  • Free 20S core particles were necessary for degrading oxidized proteins, and Ecm29-mediated dissociation was independent of the Yap1 transcription factor.

Conclusions:

  • Proteasome disassembly is a critical adaptive mechanism for cellular recovery from oxidative stress.
  • Ecm29 plays a vital role in regulating proteasome structure and function during oxidative stress.
  • The Ecm29-dependent pathway represents a parallel defense mechanism against H₂O₂-induced cellular damage.

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