Advanced Confocal Microscopy Techniques to Study Protein-protein Interactions and Kinetics at DNA Lesions
November 12th, 2017
Laser microirradiation is a useful tool for studies of DNA repair in living cells. A methodological approach for the use of UVA lasers to induce various DNA lesions is shown. We have optimized a method for local microirradiation that maintains the normal cell cycle; thus, irradiated cells proceed through mitosis.
The overall goal of these experiments is to induce DNA lesions using local micro irradiation of cells and to observe the recruitment of proteins involved in DNA repair processes.This method can help us to understand a very complex and profound question such as, how normal and cancer cells respond to DNA injury.The main advantage of this technique is that we are able to study the DNA damage response in individual live cells.Demonstrating the procedure will be by Sona Legartova, a post-doc and Jana Suchankova, a PhD student from my laboratory.To begin, cultivate HeLa cells in DMAM supplemented with 10%FBS and appropriate antibiotics.Incubate the cells at 37
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Overview
Laser microirradiation is a valuable technique for investigating DNA repair mechanisms in living cells. This study presents an optimized method for using UVA lasers to induce specific DNA lesions while preserving normal cell cycle progression.
Key Study Components
Area of Science
- DNA repair
- Cell biology
- Laser microirradiation
Background
- Understanding DNA repair is crucial for insights into cellular responses to damage.
- Laser microirradiation allows for precise induction of DNA lesions.
- Maintaining normal cell cycle is essential for accurate study of repair mechanisms.
- UVA lasers are effective in creating localized DNA damage.
Purpose of Study
- To optimize a method for local microirradiation using UVA lasers.
- To investigate the effects of induced DNA lesions on cell cycle progression.
- To enhance understanding of DNA repair processes in living cells.
Methods Used
- Utilization of UVA lasers for microirradiation.
- Monitoring cell cycle progression post-irradiation.
- Assessment of DNA repair mechanisms in irradiated cells.
- Comparison of normal and irradiated cell behavior.
Main Results
- Optimized microirradiation method successfully induced DNA lesions.
- Cells maintained normal cell cycle progression despite irradiation.
- Effective assessment of DNA repair mechanisms was achieved.
- Findings contribute to the understanding of cellular responses to DNA damage.
Conclusions
- The optimized UVA laser microirradiation method is effective for studying DNA repair.
- Maintaining the normal cell cycle is crucial for accurate experimental outcomes.
- This approach can be applied to further research in DNA damage and repair.
Frequently Asked Questions
Executive Industry Relevance
Advanced confocal microscopy combined with laser microirradiation enables precise, live-cell interrogation of protein-protein interactions and repair kinetics at DNA lesions. This capability is critical for de-risking early discovery hypotheses about DNA damage response pathways and for building predictive confidence in target validation. The approach supports translational continuity by allowing mechanistic studies in disease-relevant cellular contexts.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables direct observation of protein recruitment and interaction dynamics at DNA damage sites in live cells.
- Supports functional validation of DNA repair targets by quantifying kinetics and pathway engagement.
- Facilitates mechanistic de-risking by distinguishing cell-cycle-dependent responses using the Fucci system.
- Provides evidence for pathway selectivity and target engagement in disease-relevant models.
Screening & Assay Development
- Establishes validated live-cell systems for quantitative assessment of protein kinetics and interactions.
- Supports assay standardization through reproducible induction of DNA lesions with defined laser parameters.
- Enables high-content screening of modulators affecting DNA repair protein dynamics.
- Delivers quantitative outputs via FRAP, FLIM, and FLIM-FRET for robust compound evaluation.
Translational & Preclinical Research
- Aligns mechanistic findings with disease-relevant DNA repair phenotypes in cancer and normal cells.
- Supports biomarker discovery by linking protein interaction kinetics to cellular outcomes post-damage.
- Enables risk-adjusted advancement by providing predictive data on repair pathway modulation.
Pipeline & Workflow Integration
This methodology integrates from early discovery through lead identification, supporting both hypothesis testing and quantitative screening in live-cell systems.
- Discovery Biology: Provides real-time analysis of protein recruitment and interaction at DNA lesions for pathway clarification.
- Screening: Delivers reproducible, quantitative readouts of protein kinetics and interactions for assay development.
- Analytics: Utilizes FRAP, FLIM, and FLIM-FRET to generate comparative kinetic and interaction data across experimental conditions.
- Translational Research: Connects mechanistic protein behavior to cell-cycle phase and DNA repair outcomes in relevant models.
- Enterprise Reuse: Offers a modular platform adaptable to diverse DNA repair targets and cellular systems.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence in DNA repair target validation and pathway deconvolution.
- Operational Value: Standardizes live-cell DNA damage induction and quantitative protein analysis workflows.
- Strategic Value: Improves go/no-go decisions by providing mechanistic evidence for target engagement and pathway modulation.
- Portfolio Impact: Enables risk-adjusted prioritization of DNA repair targets and mechanisms for advancement.
Implementation Considerations
- Requires expertise in advanced confocal microscopy and live-cell imaging techniques.
- Demands access to laser microirradiation platforms and quantitative imaging infrastructure.
- Necessitates cross-team standardization of irradiation parameters and kinetic analysis protocols.
- Adaptation across cell types may require optimization of laser settings and cell cycle markers.
- Interpretation of kinetic and interaction data must consider cell-cycle phase and DNA lesion type.
Biopharma FAQs
Chapters in this video
0:05
Title
0:44
Cultivation of HeLa-derived Cell Lines
1:48
Cell Transfection
3:21
Induction of Local DNA Lesions and Confocal Microscopy
4:47
Fluorescence Lifetime Image Microscopy
6:24
FRET Efficiency Using the FLIM-FRET Script
7:48
FRAP Analysis
8:50
Results: Analysis of Recruitment of mCherry-tagged PCNA and -53BP1 at DNA Lesions in HeLa Cells
11:00
Conclusion
