DNA damage response regulator ATR licenses PINK1-mediated mitophagy

Area of Science:

• Cellular Biology
• Molecular Biology
• Genetics

Background:

• Defective DNA damage response (DDR) and mitochondrial dysfunction contribute to aging and tissue damage.
• Mitochondrial quality control (MQC) via mitophagy removes dysfunctional mitochondria.
• ATR is a key DDR regulator, but its role in non-replicating tissues and aging is unclear.

Purpose of the Study:

• To investigate the previously unknown role of ATR in mitochondrial function.
• To elucidate the mechanism by which ATR influences mitophagy and mitochondrial health.

Main Methods:

• Investigated ATR and PINK1 localization and interaction at the mitochondrial TOM/TIM complex.
• Assessed the impact of ATR deletion on mitophagy initiation and mitochondrial function.
• Analyzed oxidative phosphorylation, reactive oxygen species production, and cellular/tissue damage.

Main Results:

• ATR directly interacts with and stabilizes PINK1 at the mitochondrial translocase complex.
• ATR deletion inhibits mitophagy initiation, leading to impaired oxidative phosphorylation.
• Mitochondrial dysfunction and reactive oxygen species overproduction occur in cells and brain tissues lacking ATR.

Conclusions:

• ATR is an integral component of the PINK1-mediated MQC pathway, ensuring mitochondrial fitness.
• ATR safeguards both mitochondrial and genomic integrity under various conditions.
• ATR's dual role in DDR and mitochondrial quality control is crucial for preventing premature aging and neuropathies.