It takes three to the DNA damage response tango

Area of Science:

• Molecular Biology
• Cellular Biology
• Genetics

Background:

• The DNA damage response (DDR) is crucial for maintaining genomic stability.
• DNA double-strand breaks (DSBs) trigger a complex signaling network.
• Three PI3-kinase-related protein kinases (PIKKs) — ATM, ATR, and DNA-PK — are central regulators of the DDR.

Purpose of the Study:

• To elucidate the relative contributions of ATM, ATR, and DNA-PK in coordinating the DDR.
• To investigate the compensatory mechanisms involving ATR and DNA-PK in the absence of ATM, as observed in ataxia-telangiectasia (A-T).

Main Methods:

• Phosphoproteomic analysis was employed to quantify the activity and targets of PIKKs.
• Comparative analysis was performed in the presence and absence of ATM function.

Main Results:

• Phosphoproteomic data revealed the distinct roles and relative importance of ATM, ATR, and DNA-PK in the DDR network.
• The study demonstrated that ATR and DNA-PK can compensate for the loss of ATM function in cells from A-T patients.

Conclusions:

• ATM, ATR, and DNA-PK play coordinated yet distinct roles in the DDR.
• ATR and DNA-PK provide functional redundancy, compensating for ATM deficiency in A-T, thereby highlighting the robustness of the DDR network.