Regulation of Gene Expression in Borrelia burgdorferi

伯氏疏螺旋体基因表达的调控

基本信息

批准号：
7744019
负责人：
D. SCOTT SAMUELS
金额：
$ 35.02万
依托单位：
UNIVERSITY OF MONTANA
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-09-05 至 2012-12-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The bacterium Borrelia burgdorferi causes Lyme disease. Transmission of B. burgdorferi from its tick vector to a mammalian host and infection of the mammal require changes in the expression of a suite of genes required for transmission and infection. The change in the program of gene expression is regulated in response to environmental signals associated with tick feeding, including increased temperature. The most dramatic change in gene expression is the reciprocal regulation of the major outer surface lipoproteins, including OspC, which is required for transmission and infection. The induction of ospC gene expression is dependent on the alternative sigma factor RpoS (C38 or CS). The central hypothesis of this application is that RpoS is the key regulator of the enzootic cycle and thus serves as the target of multiple signals through several regulatory mechanisms. The specific hypotheses are that RpoS and OspC syntheses are positively and negatively regulated through several trans-acting mechanisms, including translational control by a small regulatory RNA in response to temperature and post-translational degradation by a protease. The regulation is also hypothesized to be regulated through cis-acting DNA supercoiling in response to temperature. The long-term objective of this proposal is to understand the function and regulation of OspC in transmission of B. burgdorferi and pathogenesis of Lyme disease, which will lead to improved diagnostic, prevention, and treatment strategies because expression of OspC is required for B. burgdorferi to cause Lyme disease; this is relevant to the mission of the agency to pursue fundamental knowledge for the sake of alleviating human disease. The following specific aims are proposed toward achieving this objective: 1) identify and characterize factors that repress RpoS and/or OspC syntheses; 2) identify and characterize factors that induce RpoS and/or OspC syntheses; and 3) define the temporal requirement for OspC in transmission and determine the role of RpoS in regulating OspC during mammalian infection. Genetic, biochemical, molecular, transcriptomic, and proteomic approaches will be utilized to test these hypotheses. Specifically, genes encoding regulatory factors will be disrupted and/or fused to the new inducible promoter to assay function both in culture and in a tick-mouse model, reporter fusions will be constructed to quantitatively assay gene expression, the regulatory mechanism of the small RNA will be probed by RNA binding experiments, and the global effect of DNA supercoiling on gene expression will be determined by microarray and protein identification.

描述（由申请人提供）：Burgdorferi细菌引起莱姆病。将B. burgdorferi从其壁虱载体传播到哺乳动物宿主，并感染哺乳动物，需要改变传播和感染所需的基因套件的表达。基因表达程序的变化是根据与滴答喂养相关的环境信号（包括温度升高）调节的。基因表达的最大变化是主要的外表面脂蛋白（包括OSPC）的相互调节，这是传播和感染所必需的。 OSPC基因表达的诱导取决于替代Sigma因子RPO（C38或CS）。该应用程序的中心假设是RPOS是Enzootic循环的关键调节剂，因此通过多种调节机制作为多个信号的目标。特定的假设是，RPO和OSPC合成通过多种跨作用机制进行了积极和负调控，包括小型调节RNA的转移控制，以响应蛋白酶的温度和翻译后降解。还假设该调节是通过响应温度的顺式作用DNA超串联来调节的。该提案的长期目的是了解OSPC在B. burgdorferi传播中的功能和调节以及莱姆病的发病机理，这将导致改善诊断，预防和治疗策略，因为B. burgdorferi需要表达OSPC，才能引起B. burgdorferi引起莱姆病;这与该机构为了减轻人类疾病而追求基本知识的使命。提出了以下特定目的来实现这一目标：1）确定并表征抑制RPO和/或OSPC合成的因素； 2）确定并表征诱导RPO和/或OSPC合成的因素； 3）定义OSPC在传播中的时间要求，并确定RPO在调节哺乳动物感染过程中OSPC中的作用。遗传，生化，分子，转录组和蛋白质组学方法将用于检验这些假设。 Specifically, genes encoding regulatory factors will be disrupted and/or fused to the new inducible promoter to assay function both in culture and in a tick-mouse model, reporter fusions will be constructed to quantitatively assay gene expression, the regulatory mechanism of the small RNA will be probed by RNA binding experiments, and the global effect of DNA supercoiling on gene expression will be determined by microarray and protein identification.