RpoS Regulation of Borrelia burgdorferi Genes in vivo

伯氏疏螺旋体基因的体内 RpoS 调控

• 批准号: 10232077
• 负责人: MELISSA J CAIMANO
• 金额: $ 59.38万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10232077
• 关键词: Address; Adopted; Arbovirus Infections; Area; Arthropod Vectors; Arthropods; Back; Bacteria; Bacteria sigma factor KatF protein; Binding Proteins; Black-legged Tick; Borrelia; Borrelia burgdorferi; Centers for Disease Control and Prevention (U.S.); Complex; Cues; DNA-Directed RNA Polymerase; Data; Dialysis procedure; Environment; Gatekeeping; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Holoenzymes; Human; Individual; Infection; Ixodes; Laboratories; Life Style; Lyme Disease; Mammals; Mediating; Mediator of activation protein; Membrane; Methodology; Mission; Modeling; Mus; Mutagenesis; Nature; Order Spirochaetales; OspA protein; Output; Pathway interactions; Periodicity; Phase; Proteome; Publications; Regulation; Regulatory Pathway; Regulon; Reporting; Repression; Rodent; Role; Signal Transduction; Signaling Molecule; Testing; Thinking; Ticks; Time; United States; Virulence; Work; cohort; enzootic; experimental study; gene function; holistic approach; in vivo; metabolome; programs; promoter; response; tick transmission; transcriptome; transcriptomics; vector tick

Borrelia burgdorferi (Bb), the agent of Lyme disease (LD), is maintained in nature within a complex enzootic cycle involving a mammalian reservoir host and a tick vector. To sustain this cycle, Bb must adjust its transcriptome, proteome, and metabolome to arthropod- and mammalian host-derived signals as it shuttles between the two. The Rrp2/RpoN/RpoS pathway has gained widespread recognition as a central player in borrelial gene regulation. Our laboratory has long been at the forefront of efforts to characterize the cohort of genes controlled by RpoS in both the tick and mammal. Unfortunately, we still do not know the entire output of RpoS-RNA polymerase (RNAP) holoenzyme in nature. The present proposal addresses this shortfall by combining state-of-the-art transcriptomic and mutagenesis methodologies to determine where/when individual genes contribute to RpoS's dual-host `mission'. In prior publications, we were instrumental in delineating the temporal boundaries of the RpoS-ON and –OFF states in vivo. In recent years, however, our thinking about this dichotomy has become much more nuanced. We now believe that the contours of the RpoS regulon change profoundly and in host-specific fashion during the RpoS-ON state These results, in concert with studies of the Hk1/Rrp1 pathway, give rise to our central hypothesis--the dynamic nature of the RpoS regulon reflects the confluence of non-RpoS regulatory pathways with mechanisms that govern the ON/OFF states of RpoS and the output of RpoS-RNAP. Along these lines, we now propose that the tick-phase signaling molecule c-di-GMP is crucial to this regulatory cross-talk. Moreover, we and others have found that the c-di-GMP-binding protein PlzA promotes expression of RpoS and, hence, Bb virulence in the mouse, the stage of the enzootic cycle in which the Hk1/Rrp1 pathway is OFF. Our efforts to clarify this bifunctional role of PlzA as a mediator of c-di-GMP signaling in ticks and a c-di-GMP-independent regulator of RpoS in mice takes our field into uncharted territory. Lastly, in years past, our analysis of mammalian host-adapted spirochetes cultivated in dialysis membrane chambers revealed that RpoS not only upregulates genes required for tick transmission and mammalian infection but also represses genes required for colonization and adaptation to the tick. Our recent work suggests that RpoS-RNAP directly represses transcription of tick-phase genes by occluding their σ70 promoters. We will test this `RpoS as repressor' model and explore new data that c-di-GMP antagonizes RpoS-mediated repression in mammalian host-adapted Bb. Our long-term objective is to achieve an integrative understanding of how the Rrp2/RpoN/RpoS pathway fulfills its essential mission--guiding LD spirochetes from tick to mouse and back again. We will accomplish this by defining the contours of the RpoS regulon in ticks and mice (Aim 1); clarifying the convergence of c-di-GMP- and PlzA-dependent signaling with the RpoS pathway (Aim 2); and dissecting RpoS-mediated repression of tick-phase genes and its antagonism by c-di-GMP in mammalian host-adapted Bb (Aim 3).

伯氏疏螺旋体 (Bb) 是莱姆病 (LD) 的病原体，在自然界中存在于复杂的地方性动物疫病中 涉及哺乳动物储存宿主和蜱载体的循环为了维持该循环，Bb 必须调整其自身。 转录组、蛋白质组和代谢组在穿梭时传递给节肢动物和哺乳动物宿主来源的信号 Rrp2/RpoN/RpoS 通路作为两者之间的核心角色已获得广泛认可。 我们的实验室长期以来一直处于研究疏螺旋体基因调控的最前沿。 不幸的是，我们仍然不知道蜱虫和哺乳动物中 RpoS 控制的基因的全部输出。 自然界中的 RpoS-RNA 聚合酶 (RNAP) 全酶解决了这一不足。 结合最先进的转录组学和诱变方法来确定个体的位置/时间 基因有助于 RpoS 的双宿主“使命”。在之前的出版物中，我们在描述 RpoS 的双宿主“使命”方面发挥了重要作用。 然而，近年来，我们对体内 RpoS-ON 和 –OFF 状态的时间边界进行了思考。 现在，我们相信 RpoS 调节子的轮廓已经发生了变化。 在 RpoS-ON 状态期间，这些结果与对宿主的研究一致 HK1/Rrp1 通路，产生了我们的中心假设——RpoS 调节子的动态性质反映了 非 RpoS 调控途径与控制 RpoS 的 ON/OFF 状态的机制以及 沿着这些思路，我们现在提出蜱期信号分子 c-di-GMP 是 此外，我们和其他人发现 c-di-GMP 结合蛋白 PlzA 对此至关重要。 促进 RpoS 的表达，从而促进 Bb 在小鼠中的毒力，这是地方性动物病循环的阶段，其中 我们努力阐明 PlzA 作为 c-di-GMP 信号传导介质的双功能作用。 蜱虫中的 RpoS 独立于 c-di-GMP 的调节剂将我们的领域带入了未知的领域。 在过去的几年里，我们对透析膜室中培养的适应哺乳动物宿主的螺旋体进行了分析 研究表明，RpoS 不仅上调蜱传播和哺乳动物感染所需的基因，而且还上调蜱传播和哺乳动物感染所需的基因。 我们最近的研究表明，RpoS-RNAP 会抑制蜱的定植和适应所需的基因。 通过封闭 σ70 启动子来直接抑制蜱期基因的转录，我们将测试这个“RpoS”。 抑制子模型并探索 c-di-GMP 拮抗哺乳动物中 RpoS 介导的抑制的新数据 我们的长期目标是全面了解如何适应主机 Rrp2/RpoN/RpoS 通路完成了其基本使命——引导 LD 螺旋体从蜱虫到小鼠并返回 我们将再次通过定义蜱和小鼠的 RpoS 调节子轮廓来实现这一目标（目标 1）； c-di-GMP 和 PlzA 依赖性信号传导与 RpoS 途径的融合（目标 2）； RpoS介导的蜱期基因抑制及其在哺乳动物宿主适应Bb中c-di-GMP的拮抗作用 （目标 3）。