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Updated: Jul 14, 2026
13:10
Detection and Visualization of DNA Damage-induced Protein Complexes in Suspension Cell Cultures Using the Proximity Ligation Assay
Published on: June 9, 2017
Induction of cullin 7 by DNA damage attenuates p53 function
Peter Jung1, Berlinda Verdoodt, Aaron Bailey
1Molecular Oncology, Max-Planck-Institute of Biochemistry, D-82152 Martinsried, Germany.
Summary
The tumor suppressor p53
Area of Science:
- Molecular Biology
- Cancer Biology
- Cell Cycle Regulation
Background:
- The p53 tumor suppressor is a critical transcription factor activated by DNA damage.
- Understanding p53 regulation is key to developing cancer therapies.
Purpose of the Study:
- To investigate the interaction between p53 and the cullin protein Cul7.
- To elucidate the role of Cul7 in p53-mediated cellular responses to DNA damage.
Main Methods:
- Proteomic screening to identify p53 interactors.
- Conditional microRNA expression for gene down-regulation.
- Assessment of p53 activation and cell cycle progression.
- Analysis of protein ubiquitination and degradation.
Main Results:
- Cul7 protein levels increase after DNA damage in a p53-independent manner.
- Cul7 down-regulation enhances p53-mediated cell cycle inhibition.
- Ectopic Cul7 expression inhibits p53 activation and sensitizes cells to genotoxic agents.
- Cul7/FBX29 complex does not promote p53 ubiquitination and degradation.
Conclusions:
- Cul7 negatively regulates p53 activity through mechanisms independent of ubiquitination and degradation.
- The p53-Cul7 interaction forms a negative feedback loop, similar to p53-Mdm2.
- Targeting Cul7 may enhance the efficacy of genotoxic cancer therapies for wild-type p53-expressing tumors.
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