cAMP signaling in Mycobacterium tuberculosis

结核分枝杆菌中的 cAMP 信号传导

• 批准号: 6989656
• 负责人: Kathleen A McDonough
• 金额: $ 24.03万
• 依托单位: WADSWORTH CENTER
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-15 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6989656
• 关键词: Mycobacterium tuberculosis; bacteria infection mechanism; bacterial genetics; biological signal transduction; cyclic AMP; gene expression; gene induction /repression; genetic promoter element; genetic regulatory element; genetically modified animals; host organism interaction; hypoxia; intermolecular interaction; latent bacterial disease; macrophage; microarray technology; mutant; polymerase chain reaction; protein binding; transcription factor

DESCRIPTION (provided by applicant): The long term objective of this project is to better understand how Mycobacterium tuberculosis (Mtb) establishes infection so that effective strategies can be developed to prevent it. Gene regulation is a critical aspect of Mtb's successful response to the host environment during infection. The recent finding that Mtb encodes as many as 15 adenylate cyclases (AC) suggests that cAMP signaling constitutes an important, but previously unrecognized, regulatory mechanism in Mtb. A multidisciplinary approach will address the role of cAMP signaling in Mtb, at the molecular, genetic and cellular levels, with a focus on conditions associated with latency and Mtb's interaction with macrophages. Specific aims include: Aim 1: identify, using DMA microarrays and isogenic knockout mutants, Mtb genes that are regulated by the putative cAMP-dependent transcription factor, Rv1675c, at various levels of cAMP during hypoxia; Aim 2: define and characterize a second likely cAMP-dependent regulon controlled by putative transcription factor Rv3676 in Mtb. Candidate members of this regulon will be functionally assessed by defining the role of Rv3676 binding to a DMA motif identified in their promoter regions; Aim 3: evaluate the roles of cAMP and a mammalian-type AC, Rv1625c, in Mtb's interaction with macrophages, particularly with respect to bacterial replication and trafficking; Aim 4: assess the regulation and function of a specific macrophage-induced, cAMP regulated gene within macrophages and during latency-associated conditions. Identification and characterization of cAMP-mediated gene regulation in Mtb will contribute to our understanding of the factors needed for the establishment of tuberculosis infection and disease. This work will explore a new gene regulatory network in Mtb and provide an important foundation for future work on the role of cAMP signaling in Mtb virulence gene regulation, leading to identification of potential targets for TB vaccines, therapeutics, and/ or diagnostic purposes.

本项目的长期目标是更好地了解结核分枝杆菌（Mycobacterium tuberculosis，Mtb）如何建立感染，以便开发有效的策略来预防它。基因调控是Mtb在感染过程中成功响应宿主环境的关键方面。最近发现Mtb编码多达15种腺苷酸环化酶（AC），这表明cAMP信号传导构成了Mtb中重要但以前未被认识的调节机制。多学科方法将在分子，遗传和细胞水平上解决cAMP信号在Mtb中的作用，重点关注与潜伏期和Mtb与巨噬细胞相互作用相关的条件。具体目标包括： 目标1：使用DMA微阵列和同基因敲除突变体鉴定在缺氧期间在不同cAMP水平下由推定的cAMP依赖性转录因子Rv 1675 c调节的Mtb基因; 目的2：确定和表征第二个可能的cAMP依赖性调节子控制的推定转录因子Rv 3676在结核分枝杆菌。该调节子的候选成员将通过定义Rv 3676与其启动子区中鉴定的DMA基序结合的作用来进行功能评估; 目标三：评估cAMP和Mtb型AC Rv 1625 c在Mtb与巨噬细胞相互作用中的作用，特别是在细菌复制和运输方面; 目标4：评估巨噬细胞内和潜伏期相关条件下特定巨噬细胞诱导的cAMP调节基因的调节和功能。 结核分枝杆菌中cAMP介导的基因调控的鉴定和表征将有助于我们理解建立结核感染和疾病所需的因素。这项工作将探索结核分枝杆菌中新的基因调控网络，并为今后研究cAMP信号在结核分枝杆菌毒力基因调控中的作用提供重要基础，从而确定结核疫苗，治疗和/或诊断目的的潜在靶点。