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Measurements of Physiological Stress Responses in C. Elegans
Published on: May 21, 2020
Nrf2:INrf2 (Keap1) signaling in oxidative stress
James W Kaspar1, Suryakant K Niture, Anil K Jaiswal
1Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
Free Radical Biology & Medicine
|August 12, 2009
Summary
Nuclear factor erythroid 2-related factor 2 (Nrf2) and its inhibitor INrf2 (Keap1) sense cellular stress. Nrf2 activation and deactivation protect cells from damage and promote survival.
Area of Science:
- Cellular biology
- Molecular mechanisms of stress response
Background:
- Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor crucial for cellular defense against oxidative and electrophilic stress.
- Nrf2's activity is regulated by its inhibitor, INrf2 (Keap1), which targets Nrf2 for cytoplasmic degradation.
- This regulatory system is vital for cellular protection and survival.
Purpose of the Study:
- To elucidate the distinct early and delayed mechanisms controlling the activation and deactivation of Nrf2.
- To understand how oxidative stress and specific modifications regulate Nrf2's nuclear translocation and transcriptional activity.
Main Methods:
- Investigated the roles of INrf2 cysteine 151 modification and protein kinase C (PKC) phosphorylation of Nrf2 serine 40 in Nrf2 release.
- Examined the delayed mechanism involving glycogen synthase kinase 3 beta (GSK3beta), Fyn kinase, and Nrf2 tyrosine 568 phosphorylation in Nrf2 nuclear export.
Main Results:
- Oxidative modification of INrf2 or PKC phosphorylation of Nrf2 triggers Nrf2 release from INrf2, leading to nuclear translocation and gene activation within 15 minutes.
- A delayed mechanism involving GSK3beta and Fyn kinase phosphorylates Nrf2, causing its nuclear export and subsequent degradation by INrf2.
Conclusions:
- The dynamic on/off switching of Nrf2 is a tightly regulated process essential for mitigating cellular damage.
- This regulatory pathway protects cells from free radical damage, prevents apoptosis, and ensures cell survival under stress conditions.
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