OXIDATIVE STRESS RESPONSES IN PATHOGENIC PSEUDOMONAS SPECIES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 应激反应是生物体对环境参数剧烈变化的适应能力。所有生物都有基因编码的应激反应和适应系统。氧化应激是细胞水平上一种常见的应激形式。最近在高通量实验和计算方法方面取得的革命性进展为在生物、细胞、基因组、调控网络和单个组件水平上表征氧化应激反应的分子机制提供了机会。我们建议通过重点研究氧化应激反应机制来表征应激反应和调节。我们将研究氧化应激条件下的假单胞菌菌种，以(I)识别和量化基因表达的变化，(Ii)分析蛋白质组和代谢的变化，(Iii)建立全球转录和蛋白质组学网络，以及(Iv)表征氧化应激反应网络。许多拟议的研究都是尖端的，没有在任何生物系统中进行过，它将为Alfano和Becker研究小组提供一种新的研究途径，并提供新的赠款资助机会。对模式生物维持氧化还原动态平衡的机制的研究表明，这是一个复杂而复杂的过程。细菌的抗氧化机制在共生大肠杆菌和革兰氏阳性模式生物枯草杆菌(腐生)(41)中了解得最好，然而，在非模式生物中，我们对氧化还原动态平衡的理解存在重大差距。在这里，我们试图使用系统生物学的方法来确定暴露在先天性免疫系统强烈氧化应激反应中的细菌的机制是否与自由生活或共生细菌的机制不同。具体地说，我们将使用动物病原体铜绿假单胞菌和植物病原体丁香假单胞菌。这两个物种都暴露在内源性氧化应激下，并暴露在宿主先天免疫反应产生的氧化应激下。比较和对比氧化应激反应在植物和动物致病性中的重要性将是有益的。系统生物学的方法将使人们能够更好地理解这些细菌获得的发散和趋同的进化特征。我们预计，我们将确定两个物种共同的氧化应激反应机制。我们的长期目标是了解来自生物应激的氧化还原信号是如何在动植物的革兰氏阴性病原体中介导的，以阐明氧化应激保护的机制。 这一应用的具体目的是：鉴定和定量不同氧化胁迫条件下铜绿假单胞菌和紫丁香假单胞菌基因表达的变化；分析氧化应激过程中铜绿假单胞菌和紫丁香单胞菌蛋白质组和代谢的变化；建立氧化应激诱导的转录和蛋白质组变化的全球网络；以及测试基因产物在氧化应激反应中的作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Stress response is the ability of an organism to adjust to drastic changes in environmental parameters. All living organisms have genetically encoded stress response and adaptation systems. Oxidative stress is a common stress form at the cellular level. Recent revolutionary progress in high-throughput experimental and computational approaches offer an opportunity to characterize the molecular mechanisms of oxidative stress response at the level of organisms, cells, genomes, regulatory networks and individual components. We propose to characterize stress response and regulation by focusing on oxidative stress response mechanisms. We will examine Pseudomonas bacterial species under conditions of oxidative stress to (i) identify and quantify gene expression changes, (ii) analyze proteomic and metabolic changes, (iii) build a global transcriptomic and proteomics networks, and (iv) characterize oxidative stress response networks. Much of the proposed research is cutting edge, has not been performed in any biological system, and it will allow for a new avenue of research for the Alfano and Becker research groups and new grant funding opportunities. Research into the mechanisms by which model organisms maintain redox homeostasis have revealed it to be an intricate and complex process. Bacterial antioxidant mechanisms are best understood in commensal Escherichia coli and the Gram-positive model organism Bacillus subtilis (saprophyte) (41), however, there are significant gaps in our understanding of redox homeostasis in non-model organisms. Here we seek to use systems biology approaches to determine if the mechanisms by which bacteria that are exposed to the intense oxidative stress response of the innate immune system vary from that of free-living or commensal bacteria. Specifically, we will use the animal pathogen Pseudomonas aeruginosa and the plant pathogen P. syringae. Both species are exposed to endogenous oxidative stress and exposed to oxidative stress from their host's innate immune response. It will be informative to compare and contrast the importance of oxidative stress responses in pathogenicity of plants and animals. A systems biology approach will allow for a greater understanding of the divergent and convergent evolutionary traits that these bacteria have acquired. We anticipate that we will identify oxidative stress response mechanisms that are common to both species. Our long-term goal is to understand how redox signals from biotic stress are mediated in Gram-negative pathogens of plants and animals to elucidate mechanisms of oxidative stress protection. The Specific Aims of this application are as follows: Identify and quantitate gene expression changes in P. aeruginosa and P. syringae under different oxidative stress conditions; Analyze proteomic and metabolic changes during oxidative stress in P. aeruginosa and P. syringae; Build global network of transcriptomic and proteomic changes induced by oxidative stress; and test role of gene products in oxidative stress response.