Elucidating the Orchestrated Bacterial Response to Copper Toxicity

阐明细菌对铜毒性的精心安排的反应

• 批准号: 10200089
• 负责人: Michael David Leslie Johnson
• 金额: $ 37.76万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10200089
• 关键词: Affect; Bacteria; Biological Models; Copper; DNA; Data; Immune; Mediating; Mediation; Metals; Nosocomial Infections; Nutritional Immunity; Pathway interactions; Protein Export Pathway; Proteins; Repressor Proteins; Research; Streptococcus pneumoniae; Stress; Structure; Surface; System; Techniques; Toxic effect; Vaccines; Work; Zinc; cell killing; cohort; copper poisoning; nucleotide metabolism; pathogen; response; small molecule therapeutics; sugar; therapeutic target; tool; toxic metal

PROJECT SUMMARY Despite having a dedicated copper export system, copper has been broadly toxic to bacteria since antiquity. Copper toxicity is seen in practice where copper surfaces and tools significantly reduce nosocomial infections. Furthermore, during host mediated nutritional immunity (sequestering essential metals while bombarding bacterial with toxic metals), innate immune cells kill engulfed targets using copper, which is tightly regulated within the host. However, current research is limited regarding the overarching mechanisms of toxicity and the pathways used overcome copper stress that work in conjunction with the copper export system. Through this proposal, we seek to understand how bacteria evolved to interact with toxic metals and overcome the ensuing stress. Furthermore, we seek to gather a new cohort of bacterial therapeutic targets. For our model system, we are using Streptococcus pneumoniae, a global burden, for which the vaccine only covers ~25% of known strains. Thus far, using microarray data we obtained comparing the wild type S. pneumoniae strain TIGR4 and the copper export protein deficient strain under copper stress, and an assortment of techniques, we have validated several pathways and their corresponding mechanisms. These pathways include copper poisoning nucleotide synthesis, zinc being synergistically toxic to bacteria with copper, and sugar import being vital to mediation of copper toxicity. We will focus our studies around the copper repressor protein CopY as we have data showing it not only controls the copper export system but several other systems necessary to overcome copper stress. We will characterize these CopY-controlled pathways as well as structurally characterize CopY, screen CopY for small molecule therapeutics that keep it bound to DNA, and examine CopY’s interactions with DNA and proteins. We will expound upon our current findings, explore new avenues of how copper affects S. pneumoniae, and apply our findings to other toxic metals and bacteria in hopes to elucidate the orchestrated bacterial response to metal stress.

项目总结 尽管有专门的铜出口系统，但自古以来铜对细菌就有广泛的毒性。 铜的毒性在实践中可以看到，在那里铜表面和工具可以显著减少医院感染。 此外，在宿主介导的营养免疫期间(炮击时隔离必需金属 细菌和有毒金属)，先天免疫细胞使用铜杀死被吞噬的目标，这是受到严格管制的 在主机内。然而，目前的研究仅限于毒性的主要机制和 使用的途径克服了与铜出口系统协同工作的铜压力。通过这件事 提议，我们试图了解细菌是如何进化到与有毒金属相互作用并克服随后的 压力。此外，我们寻求收集一组新的细菌治疗靶点。对于我们的模型系统，我们 正在使用肺炎链球菌，这是一个全球负担，疫苗只覆盖约25%的已知菌株。 到目前为止，使用微阵列数据，我们获得了比较肺炎链球菌野生型菌株TIGR4和铜 在铜胁迫下输出蛋白质缺乏菌株，以及各种技术，我们已经验证了几种 途径及其相应的机制。这些途径包括铜中毒核苷酸合成， 锌与铜对细菌有协同毒性，而糖进口对铜的调节至关重要 毒性。我们将围绕铜抑制蛋白拷贝进行研究，因为我们有数据表明，它不仅 控制铜出口系统，以及克服铜压力所需的其他几个系统。我们会 描述这些复制控制的途径以及结构特征复制、屏幕复制 使其与DNA结合的分子疗法，并检查Copy与DNA和蛋白质的相互作用。我们 将阐述我们目前的发现，探索铜如何影响肺炎链球菌的新途径，并应用 我们对其他有毒金属和细菌的发现，希望能阐明细菌对金属的协调反应 压力。