The antioxidant networks act as a firewall in maintenance of genomic integrity

Abstract

Reactive oxygen species (ROS) threatens genomic integrity by both destruction of DNA metabolic enzymes and oxidative DNA damage. We find a negative correlation between oxidative DNA damage and activity of antioxidant enzymes. An antioxidant network formed by interactions between the antioxidant enzymes and the proteins involved in maintenance of genomic integrity was indentified in the nucleus by multi-proteomic investigations. The protein-protein interactions in the antioxidant network are up-regulated under oxidative stress, as proved by quantitative proximity ligation assays in situ within single cells. The antioxidant network catalyzes the ROS dismutation cascade before ROS attacks DNA-processing enzymes, thereby preventing DNA and DNA metabolic enzymes from oxidative damage and dysfunction. Therefore, the antioxidant network plays a firewall role in maintenance of genomic integrity.