Mitochondrial Response to Oxidative Stress

描述（由申请人提供） 线粒体在细胞生理学和对环境胁迫的反应中起着至关重要的作用。 许多细胞毒素，包括鱼藤酮、1-甲基-4-苯基吡啶（MPP+）和百草枯，都会损害线粒体电子传递，产生ROS。 活性氧在砷、淀粉样蛋白和神经酰胺的毒性中也很重要。 线粒体被认为是ROS的潜在来源，可能导致帕金森病，衰老和其他病理条件。 由于线粒体只包含一个小的16.5 kb mtDNA基因组，仅编码13种蛋白质，因此细胞器依赖于细胞核的大多数基因产物，包括DNA复制，表达和修复所需的所有因子。 我们实验室和其他人最近的研究揭示了越来越多的蛋白质在线粒体和其他细胞区室中发挥作用。 这些蛋白质中的许多在修复线粒体DNA的氧化损伤中起作用。 线粒体病理学的一个重要后果是mtDNA突变的产生，其中许多突变具有组织特异性发病率，最常见于复制后组织，如神经和肌肉。 研究人员建议测试这一假设，即分化细胞中的线粒体可能含有与活跃分裂细胞不同的蛋白质补充，这可能使复制后细胞易于发生更高的mtDNA突变率，或可能改变细胞进入凋亡的能力。 为了实现这一目标，他们将研究氧化应激对活跃分裂的胚胎癌细胞和被诱导沿神经元通路沿着分化的细胞中线粒体蛋白质组的影响。 2-D凝胶方法和定量同位素编码亲和标签（ICAT）方法将用于比较对照细胞和暴露于氧化应激的细胞中线粒体蛋白的丰度。 广泛的蛋白质组学筛选将允许发现以前不知道在线粒体中起作用的新基因产物。 数据将进行分析，以提供新的见解蛋白质网络的作用，以修复线粒体DNA的氧化损伤或解毒活性氧。

DESCRIPTION (provided by applicant) Mitochondria play a vital role in cell physiology and the response to environmental stress. A number of cellular toxins, including rotenone, 1-methyl-4-phenylpyridine (MPP+) and paraquat act to impair mitochondrial electron transport, generating ROS. Reactive oxygen species are also important in the toxicity of arsenic, amyloid, and ceramide. Mitochondria have been viewed as a potential source of ROS that may contribute to Parkinson's disease, aging and other pathological conditions. Since mitochondria contain only a small 16.5 kb mtDNA genome, encoding only 13 proteins, the organelle depends on the nucleus for most gene products, including all of the factors required for DNA replication, expression and repair. Recent studies from our laboratory and others have revealed an increasing collection of proteins that function in both mitochondria and other cellular compartments. A number of these proteins function in repair of oxidative damage to mtDNA. One significant consequence of mitochondrial pathology is the generation of mutations in mtDNA, many of which have a tissue-specific incidence, occurring most commonly in postreplicative tissues such as nerve and muscle. The investigators propose to test the hypothesis that mitochondria in differentiated cells may contain a different complement of proteins than actively dividing cells which may predispose post-replicative cells to a higher rate of mtDNA mutations or may alter the ability of cells to enter apoptosis. To accomplish this, they will study the effect of oxidative stress on the mitochondrial proteome in both embryonal carcinoma cells that are actively dividing and in cells that have been induced to differentiate along a neuronal pathway. Both 2-D gel methods and quantitative isotope-coded affinity tag (ICAT) methods will be used to compare the abundance of mitochondrial proteins in control cells and cells exposed to oxidative stress. The broad proteomic screen will permit the discovery of novel gene products not previously known to function in mitochondria. Data will be analyzed to provide new insights into networks of proteins acting to repair oxidative damage to mtDNA or to detoxify ROS.