Regulation of gene expression in Borrelia burgdorferi

伯氏疏螺旋体基因表达的调控

• 批准号: 8775629
• 负责人: D. SCOTT SAMUELS
• 金额: $ 35.38万
• 依托单位: UNIVERSITY OF MONTANA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-05 至 2018-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8775629
• 关键词: 6S RNA; Affect; Arthropods; Bacteria; Bacteria sigma factor KatF protein; Binding; Biochemical; Biochemical Genetics; Biological Assay; Borrelia burgdorferi; Case Study; DNA-Directed RNA Polymerase; Data; Diagnostic; Endoribonucleases; Enzymes; Funding; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Guanosine Tetraphosphate; Health; Holoenzymes; Homologous Gene; Housekeeping; Human; Incidence; Infection; Ixodes; Knowledge; Laboratories; Lead; Lyme Disease; Mammals; Mediating; Messenger RNA; Microbiology; Mission; Molecular; Molecular Chaperones; Mus; Nature; Nutrient; Order Spirochaetales; Pathogenesis; Pathway interactions; Phase; Prevention; Process; Production; Proteins; Proteomics; RNA; Regulation; Regulon; Research; Ribonucleases; Role; Sigma Factor; Signal Transduction; Signaling Molecule; Small RNA; Stress; Testing; Ticks; Transcript; Translations; United States; base; disease transmission; endoribonuclease; enzootic; feeding; genetic regulatory protein; human disease; improved; in vivo; mouse model; novel; programs; promoter; response; transcriptomics; transmission process; treatment strategy; vector

DESCRIPTION (provided by applicant): Lyme disease is caused by infection with the spirochete Borrelia burgdorferi. B. burgdorferi is maintained in nature through an enzootic cycle comprising a tick vector and vertebrate host. Transmission from the tick to the mammal and establishment of the mammalian infection require sensing external signals and responding by regulating programs of gene expression. This change in gene expression is predominantly mediated by the alternative sigma factor RpoS. The central hypothesis of this application is that RpoS is the principal transcriptional regulator controlling transmission to and infection of the mammalian host, and thus serves as the target of several regulatory mechanisms. We propose to dissect the mechanisms controlling rpoS expression and RpoS activity on downstream targets. Specifically, we hypothesize that a novel rpoS transcript has a distinct role in transmission and is processed by a recently identified endoribonuclease; the signaling molecule guanosine tetraphosphate, and associated regulatory proteins, globally affect RpoS-mediated transcription and translation throughout the enzootic cycle; and a small regulatory RNA affects sigma factor selectivity and activity. The long-term objective of this proposal is to understand th role and regulation of RpoS in tick-to-mammal transmission and disease pathogenesis, which will lead to improved diagnostic, prevention, and treatment strategies because RpoS is required for B. burgdorferi to cause Lyme disease; this is relevant to the mission of the agency to "seek fundamental knowledge" for the sake of alleviating human disease. The following specific aims are proposed toward achieving this objective: 1) determine the role of, and processing mechanism for, the novel rpoS transcript; 2) elucidate the targets and function of guanosine tetraphosphate during the enzootic cycle; and 3) characterize a small RNA that regulates sigma factor selectivity. Genetic, biochemical, transcriptomic, and proteomic approaches will be utilized to test these hypotheses. Specifically, genes encoding regulatory factors (or the production of regulatory factors) will be disrupted and/or fused to an inducible promoter to assay in vivo function in a tick-mouse model.

描述（由申请人提供）：莱姆病是由伯氏疏螺旋体螺旋体感染引起的。伯氏疏螺旋体通过包括蜱媒介和脊椎动物宿主的地方性动物循环在自然界中得以维持。从蜱传播到哺乳动物以及哺乳动物感染的建立需要感知外部信号并通过调节基因表达程序做出反应。基因表达的这种变化主要由替代西格玛因子 RpoS 介导。 本申请的中心假设是，RpoS 是控制哺乳动物宿主的传播和感染的主要转录调节因子，因此可作为多种调节机制的靶标。我们建议剖析控制下游靶点上的 rpoS 表达和 RpoS 活性的机制。具体来说，我们假设一种新的 rpoS 转录物在传输中具有独特的作用，并由最近鉴定的核糖核酸内切酶加工。信号分子四磷酸鸟苷和相关的调节蛋白在整个地方性动物流行周期中全面影响 RpoS 介导的转录和翻译；小的调节RNA影响西格玛因子的选择性和活性。该提案的长期目标是了解 RpoS 在蜱到哺乳动物传播和疾病发病机制中的作用和调节，这将导致改进诊断、预防和治疗策略，因为伯氏疏螺旋体需要 RpoS 才能引起莱姆病；这与该机构为减轻人类疾病而"寻求基础知识"的使命相关。 为了实现这一目标，提出了以下具体目标：1）确定新型 rpoS 转录本的作用和处理机制； 2）阐明四磷酸鸟苷在地方性动物流行周期中的作用靶点和功能； 3) 表征调节 sigma 因子选择性的小 RNA。将利用遗传、生化、转录组和蛋白质组方法来检验这些假设。具体而言，编码调节因子（或调节因子的产生）的基因将被破坏和/或与诱导型启动子融合，以测定蜱小鼠模型中的体内功能。