Investigation of Protein Recruitment to DNA Lesions Using 405 Nm Laser Micro-irradiation

Area of Science:

• Cell Biology
• Molecular Biology
• Genetics

Background:

• The DNA Damage Response (DDR) is crucial for maintaining genome integrity.
• Studying DDR protein dynamics at DNA lesions requires methods for rapid, localized damage induction.

Purpose of the Study:

• To describe a procedure for inducing localized DNA damage in human cells using a confocal microscope.
• To enable efficient study of DNA Damage Response (DDR) protein dynamics.

Main Methods:

• Utilized a 405 nm laser line on a confocal microscope to induce localized DNA damage in human cells.
• Assessed protein accumulation at laser-induced damage sites via immunofluorescence (IF) and fluorescent reporters.
• Employed ImageJ-based scripts to monitor protein relocalization kinetics.

Main Results:

• Successfully generated spatially-delimited DNA damage in human cells.
• Visualized and quantified the recruitment of DDR factors like γ-H2A.X and RPA to damage sites.
• Demonstrated the method's resolution in distinguishing local from spread factors.

Conclusions:

• The described laser-based method simplifies the study of DNA Damage Response (DDR) dynamics.
• This technique provides high resolution for analyzing protein recruitment and kinetics at DNA damage sites.