Related Experiment Video
Updated: Jun 17, 2026
Purification of Ubiquitinated p53 Proteins from Mammalian Cells
Published on: March 21, 2022
Lessons from interconnected ubiquitylation and acetylation of p53: think metastable networks
Monsef Benkirane1, Claude Sardet, Olivier Coux
1IGH, CNRS, UPR 1142, 141 rue de la Cardonille, 34396 Montpellier cedex 5, France.
Abstract:
The critical tumour suppressor p53 plays a major role in response to DNA damage and, more generally, to genotoxic stress. The regulation of its expression and functions is under very tight controls, and involves, in particular, an extremely complex set of post-translational modifications, thanks to a variety of 'modifiers', including ubiquitylation E3s and acetyltransferases, that fine-tune the stability and activity of the protein. Work of the last few years has revealed that, in addition to targeting p53, these modifiers also modify each other, forming an intricate network of regulatory molecules and events that must be taken into account to understand p53 regulation. We propose that this network allows a metastable equilibrium that confers both sensitivity and robustness on the p53 pathway, two properties that allow the pathway to respectively answer to a variety of stimuli and return to its initial stage when the stimuli disappear.
Insights
The tumor suppressor p53 is tightly regulated by complex post-translational modifications. A newly discovered network of these modifiers ensures the p53 pathway remains sensitive yet robust to DNA damage.
Area of Science:
- Molecular Biology
- Cellular Biology
- Biochemistry
Background:
- The tumor suppressor p53 is crucial for cellular responses to DNA damage and genotoxic stress.
- p53 activity is regulated by intricate post-translational modifications, including ubiquitylation and acetylation.
- These modifications are performed by specific enzymes known as 'modifiers'.
Purpose of the Study:
- To elucidate the complex regulatory network governing p53 expression and function.
- To investigate the cross-regulatory interactions among p53 modifiers.
- To understand how this network contributes to the sensitivity and robustness of the p53 pathway.
Main Methods:
- Analysis of post-translational modification pathways affecting p53.
- Investigation of interactions between p53 modifiers (e.g., ubiquitylation E3 ligases, acetyltransferases).
- Modeling of regulatory networks to understand pathway dynamics.
Main Results:
- p53 modifiers not only target p53 but also modify each other, forming a complex regulatory network.
- This intricate network establishes a metastable equilibrium.
- The network confers both sensitivity to various stimuli and robustness for returning to a basal state.
Conclusions:
- Understanding the cross-regulation among p53 modifiers is essential for comprehending p53 pathway regulation.
- The identified network provides a framework for explaining the dual properties of sensitivity and robustness in the p53 pathway.
- This regulatory system ensures appropriate cellular responses to genotoxic stress while maintaining pathway stability.
Related Concept Videos
02:04Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein.
01:19Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
02:23Abnormal Proliferation
02:26Protein Networks
These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,...
02:04Protein-protein Interfaces
02:17Microtubule Instability