CDK1 Enhances Mitochondrial Bioenergetics for Radiation-Induced DNA Repair

• Oxygen consumption and mitochondrial ATP generation are enhanced in irradiated cells
• Upon radiation, CDK1 relocates to mitochondria
• Mitochondrial CDK1 boosts ATP generation via CI phosphorylation
• CDK1-regulated mitochondrial ATP generation favors DNA repair and cell survival

SummaryNuclear DNA repair capacity is a critical determinant of cell fate under genotoxic stress conditions. DNA repair is a well-defined energy-consuming process. However, it is unclear how DNA repair is fueled and whether mitochondrial energy production contributes to nuclear DNA repair. Here, we report a dynamic enhancement of oxygen consumption and mitochondrial ATP generation in irradiated normal cells, paralleled with increased mitochondrial relocation of the cell-cycle kinase CDK1 and nuclear DNA repair. The basal and radiation-induced mitochondrial ATP generation is reduced significantly in cells harboring CDK1 phosphorylation-deficient mutant complex I subunits. Similarly, mitochondrial ATP generation and nuclear DNA repair are also compromised severely in cells harboring mitochondrially targeted, kinase-deficient CDK1. These results demonstrate a mechanism governing the communication between mitochondria and the nucleus by which CDK1 boosts mitochondrial bioenergetics to meet the increased cellular fuel demand for DNA repair and cell survival under genotoxic stress conditions.

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