Analysis of regulatory networks in Salmonella pathogenesis.

沙门氏菌发病机制的调控网络分析。

• 批准号: 10678919
• 负责人: Andres Vazquez-Torres
• 金额: $ 49.05万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-11 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10678919
• 关键词: Active Sites; Amino Acids; Antibiotics; Antioxidants; Archaea; Area; Aspartate; Bacteremia; Bacteria; Binding; Biochemical; Biological Assay; CD4 Positive T Lymphocytes; Catalytic Domain; Cell Culture System; Client; Cues; Defect; Development; Diarrhea; Disease; Disulfides; Elements; Eukaryota; Evolution; Face; Foundations; Future; Gene Expression; Genes; Genetic Transcription; HIV; Histidine; Homeostasis; Human; Hydrophobicity; Immunocompromised Host; In Vitro; Individual; Infection; Investigation; Knowledge; Leucine; Life; Macrophage; Mediating; Modeling; Mutation; Oxidation-Reduction; Oxidoreductase; Pathogenesis; Pathogenicity Island; Persons; Pharmaceutical Preparations; Phosphorylation; Phosphotransferases; Phylogenetic Analysis; Play; Post-Translational Regulation; Prokaryotic Cells; Proteins; Publishing; Reaction; Recombinants; Regulation; Research; Role; Salmonella; Salmonella enterica; Salmonella infections; Signal Pathway; Signal Transduction; Source; Sulfhydryl Compounds; Surface; System; TXN gene; Testing; Thiol Disulfide Oxidoreductase; Type III Secretion System Pathway; Valine; Variant; Virulence; Work; analog; biophysical techniques; genetic approach; genetic regulatory protein; in silico; in vivo; insight; interfacial; neutrophil; next generation; non-typhoidal Salmonella; novel; pathogen; pathogenic bacteria; preservation; programs; protein protein interaction; response; sensor; transcription factor

PROJECT SUMMARY: Nontyphoidal Salmonella infections are frequently associated with diarrhea in healthy people. Some serovars such as Typhimurium are also common causes of bacteremia in HIV-infected people, and life- threatening disseminated complications in immunocompromised individuals with defects in neutrophils, macrophages or CD4 T cells. Sensor kinases and their cognate response regulators in two-component systems orchestrate many virulence programs in Salmonella and many other pathogenic bacteria. In the canonical activation of two-component systems, the sensor kinase is phosphorylated in response to cues encountered during colonization and infection of the mammalian host. The transfer of the phosphoryl group from the sensor kinase to the receiver domain of its cognate response regulator turns on virulence programs essential for bacterial pathogenesis. We have made the unexpected discovery that two-component response regulators are controlled by previously unknown allosteric interactions with thioredoxin. Our research has shown that thioredoxin post-translationally controls several response regulators such as OmpR, PhoP and SsrB, all of which govern key aspects of Salmonella pathogenesis. Strikingly, the post-translational control exerted by thioredoxin on two-component signaling does not rely on the universally conserved thiol-disulfide oxidoreductase enzymatic activity of this ancestral protein, but is contingent upon a hitherto uncharacterized hydrophobic interfacial surface that has been preserved throughout the evolution of thioredoxin in bacteria, archaea and eukaryotes. Our investigations indicate that most contributions of thioredoxin to Salmonella pathogenesis are independent of its oxidoreductase activity but are carried out by this newly discovered interfacial surface. The proposed research will test the hypothesis that thioredoxin leverages the binding attributes of a conserved hydrophobic patch to establish protein-protein interactions with multiple response regulators, thereby exerting broad post-translational control of two-component signaling. Specifically, we will identify the interfacial residues that mediate oxidoreductase-independent functions of thioredoxin, and will quantify the extent that the novel thioredoxin-binding face enables response regulators to activate Salmonella virulence programs. Our research will elucidate previously unappreciated elements in the regulation of two- component signaling, and will ascertain unprecedented, oxidoreductase-independent functions of thioredoxin. The knowledge gained on the novel function of thioredoxin will not only shed light on key aspects of Salmonella pathogenesis, but may ultimately broaden our understanding of a primordial function of universally-expressed thioredoxin proteins. Our work will also provide far reaching insight into the regulation of two-component systems, which represent a dominant signaling pathway in bacteria. Drugs that specifically inhibit interactions between thioredoxin and response regulators may inform the rational development of the next generation of antibiotics.

项目摘要： 健康患者的非肾脏沙门氏菌感染经常与腹泻有关。一些 诸如伤寒的血清毒素也是艾滋病毒感染者中菌血症的常见原因，生命 - 威胁要在中性粒细胞中缺陷的免疫功能低下个体中传播并发症， 巨噬细胞或CD4 T细胞。传感器激酶及其两个组件中的同源响应调节剂 系统在沙门氏菌和许多其他致病细菌中策划了许多毒力计划。在 两组分系统的规范激活，传感器激酶响应提示磷酸化 在哺乳动物宿主的殖民和感染期间遇到。磷酸基团的转移 从传感器激酶到其同源响应调节器的接收域，打开毒力程序 对于细菌发病机理必不可少的。我们已经意外发现了两个组件响应 调节剂由以前未知的变构相互作用与硫氧还蛋白进行控制。我们的研究有 表明硫氧还蛋白后翻译控制了几个响应调节剂，例如OMPR，PHOP和 SSRB，所有这些决定了沙门氏菌发病机理的关键方面。令人惊讶的是，翻译后控制 硫氧还蛋白在两个分量信号传导上施加 该祖先蛋白的氧化还原酶的酶促活性，但取决于迄今未表征 疏水性界面表面在整个硫氧还蛋白在细菌中的进化中保存下来， 古细菌和真核生物。我们的调查表明，硫氧还蛋白对沙门氏菌的大多数贡献 发病机理独立于其氧化还原酶活性，但由这种新发现的 界面表面。拟议的研究将检验硫氧还蛋白利用结合的假设 保守疏水片的属性以建立与多个反应的蛋白质 - 蛋白质相互作用 调节器，从而对两组分的信号传导进行广泛的翻译后控制。具体来说，我们会的 确定介导硫氧还蛋白的氧化还原酶非依赖性功能的界面残基，并将 量化新型硫氧还蛋白结合面的程度使响应调节剂能够激活沙门氏菌 毒力计划。我们的研究将在调节两种方面阐明先前未批准的因素 成分信号传导，并将确定硫氧还蛋白的前所未有的氧化还原酶独立的功能。 关于硫氧还蛋白的新功能所获得的知识不仅会阐明 沙门氏菌发病机理，但最终可能会扩大我们对原始功能的理解 普遍表达的硫氧还蛋白。我们的工作还将为法规提供遥远的洞察力 两个组分系统，代表细菌中的主要信号通路。具体的药物 抑制硫氧还蛋白与反应调节剂之间的相互作用可能会告知 下一代抗生素。