Integrative Modeling of Oxidative Stress and C1 Metabolism Reveals Upregulation of Formaldehyde and Downregulation of Glutathione

• 作者: Mrudhuula Mohan Prabhakar Deonikar Santhiya Kothandaram V. A. Shiva Ayyadurai Vyshali Venugopal
• 来源期刊: 美国植物学期刊(英文)
• 学科: 医学
• 关键词: C1 METABOLISM Oxidative Stress FORMALDEHYDE GLUTATHIONE FORMALDEHYDE Detoxification METHIONINE Biosynthesis Methylation Cycle Computational SYSTEMS Biology CytoSolve SYSTEMS Integration Molecular Pathways
• 年，卷（期）: 2015,（9）
• 页码范围: 1527-1542
• 页数: 16页
• 分类号: R73

摘要

This research provides, to the authors’ knowledge, the first integrative model of oxidative stress and C1 metabolism in plants. Increased oxidative stress can cause irreversible damage to photosynthetic components and is harmful to plants. Perturbations at the genetic level may increase oxidative stress and upregulate antioxidant systems in plants. One of the key mechanisms involved in oxidative stress regulation is the ascorbate-glutathione cycle which operates in chloroplasts as well as the mitochondria and is responsible for removal of reactive oxygen species (ROS) generated during photosynthetic operations and respiration. In this research, the complexity of molecular pathway systems of oxidative stress is modeled and then integrated with a previously developed in silico model of C1 metabolism system. This molecular systems integration provides two important results: 1) demonstration of the scalability of the CytoSolve&#174?Collaboratory&#153, a computational systems biology platform that allows for modular integration of molecular pathway models, by coupling the in silico model of oxidative stress with the in silico model of C1 metabolism, and 2) derivation of new insights on the effects of oxidative stress on C1 metabolism relative to formaldehyde (HCHO), a toxic molecule, and glutathione (GSH), an important indicator of oxidative homeostasis in living systems. Previous in silico modeling of C1 metabolism, without oxidative stress, observed complete removal of formaldehyde via formaldehyde detoxification pathway and no change in glutathione concentrations. The results from this research of integrative oxidative stress with C1 metabolism, however, demonstrate significant upregulation of formaldehyde concentrations, with concomitant downregulation and depletion of glutathione. Sensitivity analysis indicates that kGSH-HCHO, the rate constant of GSH-HCHO binding, VSHMT, the rate of formation of sarcosine from glycine, and , the rate of superoxide formation significantly affect formaldehyde homeostasis in the