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: 10468174
• 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/10468174
• 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; Light; Mediating; Modeling; Mutation; Oxidation-Reduction; Oxidoreductase; Pathogenesis; Pathogenicity Island; Persons; Pharmaceutical Preparations; 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; Thioredoxin-2; Type III Secretion System Pathway; Valine; Variant; Virulence; Work; analog; biophysical techniques; genetic approach; genetic regulatory protein; in silico; in vivo; insight; interfacial; macrophage; neutrophil; next generation; 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.

项目概要： 非伤寒沙门氏菌感染通常与健康人的腹泻有关。一些 鼠伤寒等血清型也是艾滋病毒感染者菌血症的常见原因，并且对生命造成影响。 中性粒细胞缺陷的免疫功能低下个体面临威胁性播散性并发症， 巨噬细胞或 CD4 T 细胞。双组分中的传感器激酶及其同源反应调节剂 系统协调沙门氏菌和许多其他致病菌的许多毒力程序。在 双组分系统的典型激活，传感器激酶响应提示而被磷酸化 在哺乳动物宿主的定植和感染过程中遇到。磷酰基的转移 从传感器激酶到其同源反应调节器的接收域开启毒力程序 对于细菌发病机制至关重要。我们意外地发现，双组分响应 调节剂由以前未知的与硫氧还蛋白的变构相互作用控制。我们的研究有 研究表明，硫氧还蛋白在翻译后控制多种反应调节因子，例如 OmpR、PhoP 和 SsrB，所有这些都控制着沙门氏菌发病机制的关键方面。引人注目的是，翻译后控制 硫氧还蛋白对双组分信号传导的作用不依赖于普遍保守的硫醇二硫化物 这种祖先蛋白质的氧化还原酶活性，但取决于迄今为止尚未表征的 在细菌硫氧还蛋白的整个进化过程中一直保留的疏水界面表面， 古细菌和真核生物。我们的研究表明，硫氧还蛋白对沙门氏菌的贡献最大 发病机制与其氧化还原酶活性无关，但由这种新发现的酶进行 界面表面。拟议的研究将检验硫氧还蛋白利用结合的假设 保守疏水补丁的属性，用于建立具有多重响应的蛋白质-蛋白质相互作用 调节器，从而对二元信号传导发挥广泛的翻译后控制。具体来说，我们将 识别介导硫氧还蛋白的氧化还原酶独立功能的界面残基，并将 量化新型硫氧还蛋白结合面使反应调节剂激活沙门氏菌的程度 毒力程序。我们的研究将阐明之前在两方面监管中未被重视的因素： 成分信号传导，并将确定硫氧还蛋白前所未有的、不依赖于氧化还原酶的功能。 对硫氧还蛋白新功能的了解不仅将揭示以下关键方面： 沙门氏菌的发病机制，但最终可能会拓宽我们对沙门氏菌原始功能的理解 普遍表达的硫氧还蛋白。我们的工作还将提供对监管的深远见解 双组分系统，代表细菌中的主要信号传导途径。药物专门 抑制硫氧还蛋白和反应调节剂之间的相互作用可能有助于合理发展 下一代抗生素。