Signal Transduction Networks in Bacillus anthracis

炭疽杆菌中的信号转导网络

• 批准号: 6855121
• 负责人: JAMES Alfred HOCH
• 金额: $ 52.35万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6855121
• 关键词: Bacillus anthracis; allosteric site; anthrax; anthrax toxin; bacterial toxins; biological signal transduction; bioterrorism /chemical warfare; drug screening /evaluation; enzyme activity; enzyme inhibitors; enzyme mechanism; gene expression; gene mutation; genetic promoter element; histidine; mass spectrometry; nuclear magnetic resonance spectroscopy; phosphotransferases; protein biosynthesis; protein structure; secretion; surface plasmon resonance; transcription factor; transposon /insertion element

DESCRIPTION (provided by applicant): Anthrax is a potentially fatal human disease caused by the Gram-positive spore-forming bacterium Bacillus anthracis. Virulence factors including the toxin crucial for B. anthracis pathogenesis are under the control of the phosphorelay signal transduction pathway that regulates post-exponential gene expression and sporulation through phosphorylation of the Spo0A response regulator transcription factor. Toxin proteins are exported to the outside of the bacterial cell where they exert their lethal effect. The research in this proposal is toward understanding anthrax toxin gene regulation and toxin secretion in order to identify new therapeutic targets for intervention and persistence. Proposed is the development of new and facile methods for gene inactivation, allele exchange and regulated gene expression in B. anthracis in order to dissect and identify those genes regulating toxin synthesis. Studies are envisioned to evaluate these genes in a pathogenesis model system leading to a more complete picture of the regulation of virulence factor synthesis and pathogenesis. The sensor histidine kinases that regulate the flow of phosphoryl groups through the phosphorelay to ultimately regulate toxin synthesis will be targets of investigation. Experiments are proposed to identify the signals recognized by B. anthracis that induce the phosphorelay. Genetic and biochemical approaches to the understanding of the mechanism by which toxin protein precursors are processed and secreted through the cytoplasmic membrane are proposed. The roles of the multiple signal peptidases in the secretion of toxin and other secreted proteins will be determined. Extensive physical characterization of the AbrB transition state regulator that represses toxin production will be undertaken to decipher how it is able to recognize seemingly random but specific DNA sequences in promoters. A combined in vivo and structural approach is proposed to pinpoint sites for intervention in the function of regulatory proteins leading to the synthesis of active anti-infective agents. Initial proof of concept studies will focus on the Spo0A response regulator for which extensive structural and biochemical information exists. This is a collaborative effort between investigators with expertise in genetics, biochemistry and structure of Bacillus regulatory proteins.

描述（由申请人提供）：炭疽是由革兰氏阳性孢子形成的细菌炭疽菌引起的潜在致命人类疾病。毒力因子在内的毒素因植物芽孢杆菌发病机理的至关重要，在磷酸层信号转导途径的控制之下，该途径通过SPO0A反应调节剂转录因子的磷酸化来调节指数后基因表达和孢子形成。毒素蛋白被导出到细菌细胞的外部，在那里它们发挥致命作用。该提案中的研究是旨在理解炭疽毒素基因调节和毒素分泌，以确定干预和持久性的新治疗靶标。提出的是开发基因失活的新方法，等位基因交换和炭疽芽孢杆菌中调节的基因表达，以剖析和鉴定那些调节毒素合成的基因。设想在发病机理模型系统中评估这些基因的研究，从而更完整地了解了毒力因子合成和发病机理的调节。调节磷酸基通过磷酸层以最终调节毒素合成的传感器组氨酸激酶将成为研究的靶标。提出了实验来识别诱导磷酸盐的炭疽芽孢杆菌识别的信号。提出了对通过细胞质膜处理和分泌毒素蛋白前体的理解机制的遗传和生化方法。将确定多个信号肽酶在毒素和其他分泌蛋白质分泌中的作用。将对抑制毒素产生的ABRB过渡状态调节剂进行广泛的物理表征，以破译其如何识别启动子中看似随机但特定的DNA序列。提出了一种合并的体内和结构方法，以查明位点以干预调节蛋白的功能，从而导致活性抗感染剂的合成。概念研究的最初证明将集中于SPO0A响应调节剂，其中存在广泛的结构和生化信息。这是具有遗传学，生物化学和杆菌调节蛋白结构的专业知识的研究人员之间的合作努力。