Campylobacter jejuni DNA methylation and gene regulation

空肠弯曲杆菌 DNA 甲基化和基因调控

• 批准号: 6810686
• 负责人: STUART A THOMPSON
• 金额: $ 32.05万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-30 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6810686
• 关键词: Campylobacter; DNA methylation; Guillain Barre syndrome; bacterial genetics; bacterial proteins; biological signal transduction; bioterrorism /chemical warfare; enzyme activity; enzyme mechanism; gastroenteritis; gene environment interaction; gene expression; gene induction /repression; methyltransferase; microarray technology; proteomics; temperature; tissue /cell culture; virulence

DESCRIPTION (provided by applicant): Campylobacter jejuni is a Category B Bioterrorism Agent as classified by the NIH. It is the leading cause of bacterial gastroenteritis in the United States, and is responsible for sporadic disease as well as food-borne and water-borne outbreaks. There are at least 2.4 million cases of C. jejuni gastroenteritis in the U.S. annually, with an incidence exceeding that of Salmonella and Shigella combined (1). C. jejuni infection is also the most common antecedent event to development of Guillain-Barr Syndrome, an acute motor paralysis apparently resulting from an autoimmune response directed at C. jejuni surface antigens. Despite the high prevalence of Campylobacter disease and more than 20 years of study, the mechanisms by which C. jejuni causes disease remain obscure. Several C. jejuni virulence factors have been identified, yet their regulatory mechanisms are largely unknown. Recent evidence implicates DNA methylation as an important signal controlling virulence gene expression in Salmonella and other bacteria. In light of this, our studies on the predicted C. jejuni DNA methylase Cj1461 showed that cj1461 was induced at 37C, the internal temperature of humans, consistent with a role in pathogenic growth adaptation. Further experiments revealed that mutation of cj1461 resulted in the dramatically altered expression of ca. 50-60 proteins, including known virulence factors and additional predicted regulatory proteins such as the orphan response regulator Cj0355. Consequently, Cj1461 appears to be involved in a complex regulatory circuit controlling expression of numerous C. jejuni genes; growth temperature is one of the signals. We now propose further study of gene regulation in C. jejuni, focusing on those proteins that are regulated by the predicted DNA methylase Cj1461 and the orphan response regulator Cj0355. We will use a combination of microarray, proteomics, and biochemical approaches to achieve the goals outlined in these three specific aims: Specific Aim 1. Determine the functional properties of Cj1461 and Cj0355 responsible for modulating virulence gene expression. Specific Aim 2. Identify the downstream targets of Cj1461 and Cj0355 to define their combinatorial impact on gene regulation. Specific Aim 3. Elucidate the upstream factors and signals controlling Cj1461 and Cj0355 expression to reveal the entire regulatory circuit.

描述（由申请人提供）：弯曲杆菌空肠是由NIH分类的B类Biotorrorism剂。它是美国细菌性胃肠炎的主要原因，并负责零星疾病以及饮食传播和水传播疫情。美国每年至少有240万例空肠肠疾病肠炎肠炎肠炎。空肠梭菌感染也是开发Guillain-Barl综合征的最常见的前期事件，这是一种急性运动瘫痪，这显然是由针对Jejuni表面抗原的自身免疫反应引起的。尽管弯曲杆菌疾病的患病率很高，并且研究了20多年，但旋转梭菌引起疾病的机制仍然晦涩难懂。已经确定了几种空肠梭菌毒力因子，但是它们的调节机制在很大程度上尚不清楚。 最近的证据表明，DNA甲基化是控制沙门氏菌和其他细菌中毒力基因表达的重要信号。鉴于此，我们对预测的J. jejuni DNA甲基酶CJ1461的研究表明，CJ1461在37C时诱导了人类的内部温度，与致病生长适应中的作用一致。进一步的实验表明，CJ1461的突变导致Ca的表达发生了巨大变化。 50-60蛋白，包括已知的毒力因子和其他预测的调节蛋白，例如孤儿反应调节剂CJ0355。因此，CJ1461似乎参与了控制众多空肠基因表达的复杂调节回路。生长温度是信号之一。 现在，我们提出了对空肠梭菌中基因调节的进一步研究，重点是那些受预测的DNA甲基酶CJ1461和孤儿反应调节剂CJ0355调节的蛋白质。我们将使用微阵列，蛋白质组学和生化方法的结合来实现这三个特定目标中概述的目标： 具体目的1。确定负责调节毒力基因表达的CJ1461和CJ0355的功能特性。 具体目标2。确定CJ1461和CJ0355的下游靶标，以定义其组合对基因调节的影响。 具体目标3。阐明控制CJ1461和CJ0355表达的上游因子和信号以揭示整个监管电路。