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Characterizing DNA Repair Processes at Transient and Long-lasting Double-strand DNA Breaks by Immunofluorescence Microscopy
Published on: June 8, 2018
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Multi-layered chromatin proteomics identifies cell vulnerabilities in DNA repair
Gianluca Sigismondo1, Lavinia Arseni2, Nicolàs Palacio-Escat1
1Division of Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
Nucleic Acids Research
|January 11, 2023
Summary
The DNA damage response (DDR) relies on chromatin interactions. This study reveals new proteins and histone modifications regulating DNA repair, offering potential cancer therapy targets.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- The DNA damage response (DDR) is crucial for maintaining genome stability and preventing cancer.
- Chromatin structure, including histone post-translational modifications (hPTMs) and associated proteins, plays a key role in regulating the DDR.
- Dysregulation of the DDR is linked to carcinogenesis and presents therapeutic targets for cancer treatment.
Purpose of the Study:
- To characterize chromatin-mediated functional interactions during DNA double-strand break (DSB) repair using multi-layered proteomics.
- To identify novel DDR-associated factors and their roles in different repair pathways.
- To investigate the dynamics of hPTMs at DSBs and their contribution to the DDR.
Main Methods:
- Multi-layered proteomics was employed to analyze chromatin interactions, hPTMs, and the DNA-bound proteome.
- High temporal resolution was used to capture dynamic changes during DSB repair.
- Functional characterization of novel chromatin-associated proteins involved in non-homologous end-joining (NHEJ) and homologous recombination (HR) pathways.
Main Results:
- Illuminated the dynamic behavior of known and novel DDR factors at chromatin and DSBs.
- Functionally attributed novel proteins to NHEJ, HR, and DSB repair pathway choice.
- Identified ATAD2, TPX2, and G9A as regulators of HR and sensitivity to poly-ADP-ribose polymerase inhibitors.
- Distinguished global hPTMs from DSB-specific modifications and profiled their dynamics.
- Linked G9A-mediated H3K56 monomethylation to HR-mediated DSB repair.
Conclusions:
- Provided a dynamic, chromatin-centered view of the DDR.
- Identified novel regulators of DSB repair pathways, including HR.
- Highlighted the role of specific hPTMs and proteins in DDR pathway choice and therapeutic sensitivity.
- The findings offer potential avenues for identifying new mechanistic links and vulnerabilities in cancer therapy targeting DSB repair.
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