Monitoring Chk1 kinase activity dynamics in live single cell imaging assays

Area of Science:

• Cell Biology
• Molecular Biology
• Genetics

Background:

• The ATR/Chk1 pathway is crucial for cell cycle control, DNA damage response (DDR), and maintaining genome integrity.
• Chk1 kinase is active during normal S phase and in response to genotoxic stress, preventing premature mitosis with unreplicated DNA.

Approach:

• Developed a Förster Resonance Energy Transfer (FRET)-based reporter for Chk1 kinase activity.
• Utilized live single-cell imaging assays for high-sensitivity, time-resolved monitoring of Chk1 activation kinetics.
• Established a comprehensive image analysis pipeline for quantifying Chk1 activity.

Key Points:

• Directly monitored Chk1 activity dynamics during unperturbed S phase and following genotoxic stress.
• Elucidated the mechanisms underlying Chk1 activation in real-time.
• Demonstrated the utility of FRET reporters for studying cell cycle and DDR interplay.

Conclusions:

• The FRET reporter provides unprecedented sensitivity and temporal resolution for studying Chk1 kinase activity.
• This tool facilitates a deeper understanding of cell cycle regulation and DNA repair mechanisms.
• The presented methodology and analysis pipeline enable robust investigation of Chk1 dynamics in live cells.