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: 7058223
• 负责人: MICHAEL V. NORGARD
• 金额: $ 38.08万
• 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 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7058223
• 关键词: Borrelia; DNA directed RNA polymerase; Lyme disease; affinity chromatography; bacteria infection mechanism; bacterial genetics; bacterial proteins; gel mobility shift assay; gene expression; genetic mapping; genetic regulation; laboratory mouse; laboratory rat; microarray technology; oligonucleotides; transcription factor; virulence

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）：Borrelia Burgdorferi（BB），莱姆病螺旋体，随着其自然界在其多样化的tick虫和哺乳动物宿主之间的自然循环，经历了戏剧性的适应性变化。但是，关于调节BB感染性和毒力的遗传调节网络知之甚少。 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.这项研究提议建立在最初的观察结果上，并在遗传和分子水平上研究新型的RPON-RPOS调节途径，因为它与BB的感染性和毒力有关。在特定的目标1中，我们将确定RPON-RPOS调节途径的激活因子。研究将着重研究BB的“反应调节蛋白2”（RRP2）的作用，该作用被预测为转录增强子结合蛋白。在特定目标2中，我们将检查RPON控制RPO的表达的机制，重点是（i）映射RPOS启动子，以及（ii）评估RPON及其激活剂（RRP2）与RPOS启动子和上游区域的结合。特定目标3中的研究将研究RPON-RPOS途径调节原型差异调节脂蛋白的表达的机制。将重点放在分析OSPC启动子的关键特征上，该特征通过RPOS通过RPOS来控制其控制。在特定的目标4中，我们将研究RPON-RPOS途径对BB感染动物，定居tick，载体传播并引起疾病的能力的影响。最后，在特定的目标5中，我们将使用DNA微阵列在全球范围内识别受RPON-RPOS调节途径影响的BB基因。这些合并的研究将有助于进一步表征BB中新型的RPON-RPOS调节途径，并有可能识别感染 - 和/或毒力相关的基因，这些基因有助于BB复杂的寄生策略的许多方面。