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Updated: May 29, 2026
10:55
Purification of Ubiquitinated p53 Proteins from Mammalian Cells
Published on: March 21, 2022
The nucleolus directly regulates p53 export and degradation.
Mark T Boyd1, Nikolina Vlatkovic, Carlos P Rubbi
1p53/MDM2 Research Group, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool L69 3GA, England, UK.
The Journal of Cell Biology
|September 7, 2011
Summary
Cellular stress disrupts the nucleolus, affecting p53 protein degradation. This study shows nucleoli directly control p53 regulation, impacting its stability and cellular localization.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Stress-induced nucleolar disruption correlates with impaired p53 degradation.
- The nucleolus's role in p53 regulation is debated: direct control versus indirect effects via protein redistribution.
Purpose of the Study:
- To investigate whether the nucleolus directly controls p53 regulation or indirectly influences it.
- To elucidate the mechanisms by which nucleolar integrity affects p53 stability.
Main Methods:
- Utilized heterokaryon transport experiments, photobleaching, and micronucleation.
- Performed subcellular fractionation and nucleolar isolation to analyze p53 distribution.
- Investigated ubiquitylated p53 localization and nucleolar protein interactions.
Main Results:
- Demonstrated that p53 regulatory events are directly controlled by intact nucleolar structure and function.
- Confirmed a specific distribution of ubiquitylated p53 supporting direct nucleolar regulation.
- Identified two distinct p53 export pathways: one stress-sensitive and one stress-insensitive, the latter dependent on nucleolar activities.
Conclusions:
- The nucleolus plays a direct, essential role in regulating p53 stability and degradation.
- Nucleolar function is critical for controlling p53 cellular localization and response to stress.
- The nucleolus directly modulates p53 export, influencing its availability and activity.
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