Signal Transduction Networks in Bacillus Anthracis

炭疽杆菌中的信号转导网络

• 批准号: 7264970
• 负责人: JAMES Alfred HOCH
• 金额: $ 46.6万
• 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 2012-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7264970
• 关键词: Signal; Transduction; Networks; Bacillus; Anthracis

DESCRIPTION (provided by applicant): The regulation of sporulation and its interplay with the complex cellular processes that control growth and division in Bacillus species has been compromised in Bacillus anthracis by the virulence plasmids pXO1 and pXO2 with their own regulatory agenda. The research we have accomplished and propose here in B. anthracis is dedicated to unraveling the complications that their presence generates in the basic molecular interactions that drive cell growth and development. Anthrax toxin expression represents the ultimate end product of the interaction and coordination of the cellular and gene specific regulatory circuits. We have developed transposon vectors to probe the genes affecting the regulatory circuits. Transposon insertion strains will be isolated using specific reporters that assess the transcriptional expression of the genes encoding the protective antigen, and its major known regulators, AtxA and PagR. Our studies indicate that post-translational regulation of the activity of AtxA occurs by phosphorylation through the PTS sugar transport system. The specific components of this system responsible for AtxA regulation will be identified by mutagenesis experiments. The location of the phosphorylated residues on AtxA will be determined. The virulence plasmids were found to encode genes structurally similar to the sensor domain of a major sporulation sensor kinase and the expression of these genes was shown to inhibit that kinase and sporulation. Studies will be undertaken to identify the signal ligand bound to these proteins that allows the plasmids to affect the cellular circuits for sporulation. Structural studies that visualized the protein folds of the plasmid sensor domains and that of the PagR protein will be continued and focused on the DNA-bound structure of PagR and sporulation sensor kinases. Alanine scanning mutagenesis will be used to probe for possible effectors of PagR activity. A markerless deletion program on sporulation sensor kinases will be undertaken to determine those kinases responsible for allowing toxin synthesis during growth. This program has the goal of generating knowledge of the pathogenic regulatory mechanisms employed by toxin producing spore-forming bacteria for which little is known.

描述（由申请人提供）：调节孢子形成及其与复杂的细胞过程的相互作用，该过程控制了芽孢杆菌物种中控制生长和分裂的复杂细胞过程，已通过毒力质粒PXO1和PXO2与自己的调节性议程在炭疽芽孢杆菌中受到损害。我们在B.炭疽芽孢杆菌中完成并提出的研究致力于揭示其存在在促进细胞生长和发育的基本分子相互作用中产生的并发症。炭疽毒素的表达代表了细胞和基因特异性调节回路的相互作用和协调的最终最终产物。我们已经开发了转座量向量来探测影响调节回路的基因。转座插入菌株将使用特定的记者进行分离，该特定报告者评估编码保护性抗原的基因的转录表达及其主要已知调节剂ATXA和PAGR。我们的研究表明，通过PTS糖传输系统磷酸化发生ATXA活性的翻译后调节。负责ATXA调控的该系统的特定组件将通过诱变实验确定。将确定AT​​XA上磷酸化残基的位置。发现毒力质粒在结构上与主要孢子孢子传感器激酶的传感器结构域进行编码，并且这些基因的表达被证明抑制了这种激酶和孢子形成。将进行研究，以识别与这些蛋白质结合的信号配体，从而使质粒影响细胞回路以进行孢子形成。可视化质粒传感器结构域的蛋白质褶皱和验pa蛋白的蛋白质褶皱的结构研究将继续并集中在pag和孢子传感器激酶的DNA结合结构上。丙氨酸扫描诱变将用于探测验证活性的可能效应子。将进行一项无标记的缺失程序，以确定负责在生长过程中允许毒素合成的激酶。该程序的目的是产生对毒素产生孢子形成细菌所采用的致病调节机制的知识。