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Updated: Jun 25, 2026

Quantitative Detection of DNA-Protein Crosslinks and Their Post-Translational Modifications
Published on: April 21, 2023
Regulating post-translational modifications of the eukaryotic replication clamp PCNA
1Cancer Research UK London Research Institute, Clare Hall Laboratories, Blanche Lane, South Mimms, EN6 3LD, United Kingdom. helle.ulrich@cancer.org.uk
Abstract:
Modifications of the eukaryotic sliding clamp, proliferating cell nuclear antigen (PCNA), by ubiquitin and the ubiquitin-related protein SUMO, are well known to influence the choice of pathways for the processing of DNA lesions during replication. Over the past few years, significant progress has been made not only with respect to the molecular consequences that each of the modifications has for the properties of PCNA, but also in terms of the cellular signals that elicit the ubiquitylation or sumoylation of PCNA in the appropriate situations. This review will discuss the regulatory mechanisms that control PCNA modifications, emphasizing the important role of the DNA template on which PCNA acts in activating the relevant ubiquitin and SUMO conjugation factors, and pointing out similarities as well as some interesting variations among different organisms in the regulation of PCNA modifications.
Insights
Ubiquitin and SUMO modifications of proliferating cell nuclear antigen (PCNA) regulate DNA repair pathways during replication. This review details the regulatory mechanisms controlling PCNA modifications, emphasizing DNA template roles.
Area of Science:
- Molecular Biology
- Cell Biology
- Genetics
Background:
- Proliferating cell nuclear antigen (PCNA) is a eukaryotic sliding clamp crucial for DNA replication and repair.
- PCNA undergoes post-translational modifications, including ubiquitylation and SUMOylation, which dictate DNA lesion processing pathways.
- These modifications are critical for maintaining genome stability during DNA replication stress.
Purpose of the Study:
- To review the regulatory mechanisms controlling PCNA ubiquitylation and SUMOylation.
- To highlight the role of the DNA template in activating PCNA modification factors.
- To compare regulatory similarities and variations across different organisms.
Main Methods:
- Literature review of recent studies on PCNA modifications.
- Analysis of molecular mechanisms governing ubiquitylation and SUMOylation.
- Comparative analysis of regulatory pathways in various eukaryotic organisms.
Main Results:
- Detailed understanding of how ubiquitylation and SUMOylation alter PCNA properties.
- Identification of cellular signals that trigger specific PCNA modifications.
- Emphasis on the DNA template's role in recruiting and activating conjugation factors.
Conclusions:
- PCNA modifications are tightly regulated to ensure appropriate DNA repair pathway choice.
- The DNA template is a key determinant in orchestrating PCNA ubiquitylation and SUMOylation.
- Conserved and divergent mechanisms regulate PCNA modifications across eukaryotes.
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