The RpoN-RpoS regulatory pathway in Borrelia burgdorferi

伯氏疏螺旋体中的 RpoN-RpoS 调控途径

• 批准号: 7433723
• 负责人: MICHAEL V. NORGARD
• 金额: $ 38.78万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2009-08-13
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7433723
• 关键词: Animals; Bacteria sigma factor KatF protein; Binding; Borrelia; Borrelia burgdorferi; Complex; DNA Microarray Chip; DNA Microarray format; Disease; Genes; Genetic; Infection; Lipoproteins; Maps; Membrane; Modeling; Molecular Genetics; Nature; OmpR protein; OspC protein; Pathway interactions; Promoter Regions; Proteins; RNA polymerase sigma 54; Regulatory Pathway; Role; Sigma Factor; Ticks; Virulence; enhancer binding protein; novel; promoter; vector

DESCRIPTION (provided by applicant): Borrelia burgdorferi (Bb), the Lyme disease spirochete, undergoes dramatic adaptive changes as it cycles in nature between its diverse tick and mammalian hosts. However, little is known regarding the genetic regulatory networks that modulate Bb's infectivity and virulence. Recently, we discovered a novel regulatory pathway in Bb, wherein one alternative sigma factor (sigma N, sigmaN, sigma54, RpoN) regulates the expression of another alternative sigma factor (sigma S, sigmaS, sigma38, RpoS) which, in turn, governs the expression of key membrane lipoproteins associated with borrelial virulence. This study proposes to build on this initial observation and investigate, at the genetic and molecular levels, the novel RpoN-RpoS regulatory pathway as it pertains to Bb's infectivity and virulence. In Specific Aim 1, we will identify the activator of the RpoN-RpoS regulatory pathway; studies will focus on examining a role for the "response regulator protein 2" (Rrp2) of Bb that is predicted to be a transcriptional enhancer-binding protein. In Specific Aim 2, we will examine the mechanism by which RpoN controls the expression of RpoS, with emphasis on (i) mapping the rpoS promoter and (ii) assessing the binding of RpoN and its activator (Rrp2) to the rpoS promoter and upstream regions. Studies in Specific Aim 3 will investigate the mechanism by which the RpoN-RpoS pathway regulates the expression of a prototypic differentially regulated lipoprotein, OspC. Emphasis will be placed on analyzing key features of the ospC promoter that engender its control by RpoN via RpoS. In Specific Aim 4, we will examine the influence of the RpoN-RpoS pathway on Bb's ability to infect animals, colonize ticks, be vector-transmitted, and cause disease. Finally, in Specific Aim 5, we will use DNA microarrays to identify more globally those genes of Bb influenced by the RpoN-RpoS regulatory pathway. These combined studies will be instrumental in further characterizing the novel RpoN-RpoS regulatory pathway in Bb and for potentially identifying infection- and/or virulence-associated genes that contribute to many aspects of Bb's complex parasitic strategy.

描述（由申请人提供）：莱姆病螺旋体伯氏疏螺旋体（Bb）在其不同蜱和哺乳动物宿主之间自然循环时经历显著的适应性变化。然而，很少有人知道关于基因调控网络，调节Bb的感染性和毒力。最近，我们在Bb中发现了一种新的调节途径，其中一种替代性σ因子（σ N，σ N，σ 54，RpoN）调节另一种替代性σ因子（σ S，σ S，σ 38，RpoS）的表达，所述另一种替代性σ因子反过来支配与疏螺旋体毒力相关的关键膜脂蛋白的表达。本研究建议建立在这一初步观察和调查，在遗传和分子水平上，新的RpoN-RpoS调节途径，因为它涉及到Bb的感染性和毒力。在具体目标1中，我们将确定RpoN-RpoS调节途径的激活剂;研究将集中在研究Bb的“反应调节蛋白2”（Rrp 2）的作用，该蛋白被预测为转录增强子结合蛋白。在特定目标2中，我们将研究RpoN控制RpoS表达的机制，重点是（i）定位rpoS启动子和（ii）评估RpoN及其激活剂（Rrp 2）与rpoS启动子和上游区域的结合。特定目标3的研究将调查RpoN-RpoS途径调节原型差异调节脂蛋白OspC表达的机制。重点将放在分析的ospC启动子，产生其控制RpoN通过RpoS的关键特征。在具体目标4中，我们将研究RpoN-RpoS途径对Bb感染动物、定殖蜱、媒介传播和致病能力的影响。最后，在具体目标5中，我们将使用DNA微阵列来更全面地识别受RpoN-RpoS调控途径影响的Bb基因。这些综合研究将有助于进一步表征Bb中的新型RpoN-RpoS调控途径，并可能识别与Bb复杂寄生策略的许多方面有关的感染和/或毒力相关基因。