Inactivation of Ras1 in Fission Yeast Aggravates the Oxidative Stress Response Induced by Tert Butyl Hydroperoxide (tBHP)

Ras proteins are small GTPases and function as molecular switches to regulate cellular homeostasis. Ras-dependent signalling pathways regulate several essential processes such as cell cycle progression, growth, migration, apoptosis, and senescence. The dysregulation of Ras signaling pathway has been linked to several pathological outcomes. A potential role of RAS in regulating the redox signalling pathway has been established that includes the manipulation of ROS levels to provide a redox milieu that might be conducive to carcinogenesis. Reactive oxygen species (ROS) and mitochondrial impairment have been proposed as major factors affecting the physiology of cells and implicated in several pathologies. The present study was conducted to evaluate the role of Ras1, tert Butyl hydroperoxide (tBHP), and antimycin A in oxidative stress response in Schizosaccharomyces pombe cells. We observed decreased cell survival, higher levels of ROS, and mitochondrial dysfunctionality in ras1 Δ cells and tBHP as well as respiratory inhibitor, antimycin A treated wild type cells. Furthermore, these defects were more profound in ras1 Δ cells treated with tBHP or antimycin A. Additionally, Ras1 also has been shown to regulate the expression and activity of several antioxidant enzymes like glutathione peroxidase (GSH-Px), glutathione- S -transferase (GST), and catalase. Together, these results suggest the potential role of S. pombe Ras1 in mitigating oxidative stress response.