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Updated: Aug 7, 2026
A Simple, Rapid, and Quantitative Assay to Measure Repair of DNA-protein Crosslinks on Plasmids Transfected into Mammalian Cells
Published on: March 5, 2018
Repair of DNA-protein cross-links in mammalian cells
Joyce T Reardon1, Yuan Cheng, Aziz Sancar
1Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA.
Abstract:
DNA-protein cross-links are generated by both endogenous and exogenous DNA damaging agents, as intermediates during normal DNA metabolism, and during abortive base excision repair. Cross-links are relatively common lesions that are lethal when they block progression of DNA polymerases. DNA-protein cross-links may be broadly categorized into four groups by the DNA and protein chemistries near the cross-link and by the source of the cross-link: DNA-protein cross-links may be found (1) in nicked DNA at the 3' end of one strand (topo I), (2) in nicked DNA at the 5' end of one strand (pol beta), (3) at the 5' ends of both strands adjacent to nicks in close proximity (topo II; Spo 11), and (4) in one strand of duplex DNA (UV irradiation; bifunctional carcinogens and chemotherapeutic agents). Repair mechanisms are reasonably well-defined for groups 1 and 3, and suggested for groups 2 and 4. Our work is focused on the recognition and removal of DNA-protein cross-links in duplex DNA (group 4).
Insights
DNA-protein cross-links are common DNA lesions that can be lethal if they block DNA replication. This study focuses on understanding the repair of these cross-links in duplex DNA.
Area of Science:
- Molecular Biology
- DNA Repair Mechanisms
- Biochemistry
Background:
- DNA-protein cross-links (DPCs) are DNA lesions formed by endogenous and exogenous agents, and during DNA metabolism.
- These cross-links can be lethal to cells by obstructing DNA polymerase progression.
- DPCs are classified into four groups based on their chemical nature and origin.
Purpose of the Study:
- To investigate the recognition and removal of DNA-protein cross-links.
- Specifically focusing on DPCs found in duplex DNA (Group 4).
Main Methods:
- The study focuses on Group 4 DPCs, which occur in one strand of duplex DNA.
- Mechanisms for Group 4 DPC repair are being investigated, building on known pathways for other DPC types.
Main Results:
- Repair mechanisms for Group 1 and Group 3 DPCs are well-established.
- Repair pathways for Group 2 and Group 4 DPCs are suggested but require further definition.
- The research specifically targets the understanding of Group 4 DPC repair.
Conclusions:
- DNA-protein cross-links represent a significant challenge to genomic integrity.
- Further research is needed to fully elucidate the repair pathways for all DPC categories, particularly Group 4.
- Understanding DPC repair is crucial for addressing DNA damage caused by various agents.
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