Related Experiment Video
Updated: Mar 8, 2026

In-vitro Reconstitution of Bacterial Ubiquitination and VCP/p97-mediated Elimination
Published on: January 2, 2026
p97 Negatively Regulates NRF2 by Extracting Ubiquitylated NRF2 from the KEAP1-CUL3 E3 Complex
Shasha Tao1, Pengfei Liu1, Gang Luo1
1Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona, USA.
The p97 protein complex is crucial for degrading the NRF2 protein, a key player in cellular defense against oxidative stress. Understanding this pathway opens new avenues for cancer therapy targeting p97 and NRF2.
Area of Science:
- Molecular Biology
- Cellular Biology
- Biochemistry
Background:
- Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor vital for cellular defense against oxidative and electrophilic stress.
- The canonical pathway involves NRF2 ubiquitylation by the KEAP1-CUL3-RBX1 E3 ligase complex and subsequent proteasomal degradation.
- The precise mechanism linking the CUL3 complex to proteasomal degradation remained unclear.
Purpose of the Study:
- To elucidate the role of p97, a ubiquitin-dependent ATP segregase, in the degradation pathway of NRF2.
- To investigate the interaction between p97 and the KEAP1-CUL3 E3 ligase complex in regulating NRF2 stability.
Main Methods:
- Biochemical assays to study protein-protein interactions.
- Ubiquitin-proteasome system (UPS) analysis.
- Cellular assays to assess NRF2 degradation and activity.
Main Results:
- p97, with cofactors UFD1/NPL4 and UBXN7, extracts ubiquitylated NRF2 from the KEAP1-CUL3 E3 complex.
- This extraction facilitates the efficient proteasomal degradation of NRF2.
- p97 acts as a negative regulator of NRF2 stability within the canonical degradation pathway.
Conclusions:
- p97 is essential for the proteasomal degradation of NRF2 by disassembling the KEAP1-CUL3-NRF2 complex.
- NRF2's role in chemoresistance and the therapeutic interest in p97 inhibitors suggest dual p97/NRF2 inhibition as a potential cancer treatment strategy.
Related Concept Videos
The Unfolded Protein Response
Regulation of the Unfolded Protein Response
Regulation of Nuclear Protein Sorting
Regulated Protein Degradation
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Regulated Protein Degradation
Receptor Downregulation in MVBs
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR...

