Analysis of pH dependent regulation in B. burgdorferi

伯氏疏螺旋体 pH 依赖性调节分析

• 批准号: 6646732
• 负责人: James A. Carroll
• 金额: $ 15.66万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6646732
• 关键词: Borrelia; DNA footprinting; Ixodes; Lyme disease; SDS polyacrylamide gel electrophoresis; acid base balance; affinity chromatography; arthropod borne communicable disease; bacteria infection mechanism; electroporation; environmental adaptation; flow cytometry; gel mobility shift assay; genetic regulation; green fluorescent proteins; mass spectrometry; matrix assisted laser desorption ionization; molecular cloning; molecular pathology; polymerase chain reaction; protein binding; proteomics; regulatory gene

DESCRIPTION (provided by applicant): Lyme disease is a multi-systemic disorder caused by Borrelia burgdorferi that spreads to mammals by the bite of an Ixodes tick. In the U.S. alone over 17,000 cases were reported in 2000, making it the number one reportable arthropod-borne infectious disease. In unfed, infected ticks the bacteria reside in the tick midgut, which has a pH/temperature of 8.0-8.4/23degreesC. During tick feeding and transmission the spirochetes experience a shift in pH/temperature from 8.0-8.4/23degreesC to 6.0- 7.4/35degreesC due to the influx of blood from the host. B. burgdorferi adapts to its new surroundings by altering the expression of different genes in response to environmental cues, such as changes in pH and temperature. We propose to delineate the molecular mechanisms that are involved in gene regulation in response to pH. Using affinity chromatography, mass spectroscopy and DNase I footprinting we propose to identify, characterize and inactivate the positive regulator of paralogous gene family 54 in B. burgdorferi. This gene family contains 13 genes that are located on linear plasmids. The role of these genes in the infection or adaptation process is unknown, but gene family members bba64, bba65, bba66, and bba73 are regulated by changes in pH and have been implicated in contributing to acute Lyme arthritis in model systems. By understanding how this bacterium is able to sense the environment and alter gene expression in response to changes in environmental cues, we hope to gain insight into i) the regulatory components necessary for adaptation and infection and ii) the role of pH regulation of target genes in mammalian pathogenesis.

描述（由申请人提供）：莱姆病是一种由伯氏疏螺旋体引起的多系统疾病，通过硬蜱叮咬传播给哺乳动物。仅在美国，2000 年就报告了 17,000 多例病例，使其成为第一大可报告的节肢动物传播传染病。在未喂食的受感染蜱中，细菌驻留在蜱中肠中，其 pH 值/温度为 8.0-8.4/23 摄氏度。在蜱进食和传播过程中，由于宿主血液的流入，螺旋体的 pH/温度从 8.0-8.4/23 摄氏度转变为 6.0-7.4/35 摄氏度。伯氏疏螺旋体通过改变不同基因的表达来响应环境信号（例如 pH 值和温度的变化）来适应新环境。我们建议描述参与 pH 响应基因调控的分子机制。我们建议使用亲和色谱、质谱和 DNase I 足迹来识别、表征和灭活伯氏疏螺旋体中旁系同源基因家族 54 的正调节因子。该基因家族包含 13 个位于线性质粒上的基因。这些基因在感染或适应过程中的作用尚不清楚，但基因家族成员 bba64、bba65、bba66 和 bba73 受 pH 变化的调节，并与模型系统中的急性莱姆关节炎有关。通过了解这种细菌如何感知环境并根据环境线索的变化改变基因表达，我们希望深入了解 i) 适应和感染所需的调节成分，以及 ii) 靶基因 pH 调节的作用在哺乳动物的发病机制中。