Characterization of cyclic-GMP-cAMP regulation in Vibrio cholerae

霍乱弧菌中环 GMP-cAMP 调节的特征

• 批准号: 10371521
• 负责人: VINCENT T LEE
• 金额: $ 22.01万
• 依托单位: UNIV OF MARYLAND, COLLEGE PARK
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10371521
• 关键词: Bacterial Adhesins; Binding; Binding Proteins; Biochemical; Biochemical Genetics; Biological Assay; Blood capillaries; Cells; Characteristics; Chemotaxis; Cyclic AMP; DNA Structure; Defect; Development; Dinucleoside Phosphates; Disadvantaged; Down-Regulation; Enzymes; Escherichia coli; Family; Genes; Genetic; Genetic Transcription; Genome; Hemagglutinin; Homeostasis; Horizontal Gene Transfer; Individual; Infant; Infection; Island; Lead; Ligands; Light; Mannose; Mediating; Metabolism; Mutate; Nucleotides; Open Reading Frames; Operon; Organism; Pathogenesis; Pathogenicity; Pathway interactions; Periodicity; Phospholipase; Phospholipases A; Pilum; Process; Production; Prokaryotic Cells; Proteins; Proteomics; Pyruvate Carboxylase; RNA; Radial; Radiolabeled; Regulation; Regulatory Pathway; Regulon; Reporting; Scanning; Signal Pathway; Signal Transduction; Signaling Molecule; Single Nucleotide Polymorphism; Small RNA; Structure; Surface; Techniques; Testing; Vibrio; Vibrio cholerae; Virulence; affinity labeling; base; cellulose synthase; genetic approach; lipid metabolism; mouse model; mutant; overexpression; pandemic disease; pathogen; potassium ion; promoter; receptor; receptor binding; screening; transcription factor

ABSTRACT Vibrio cholerae is a pathogen capable of causing worldwide pandemics including seven in the scientific record. The seventh pandemic El Tor biotype that displaced the classical biotype responsible for the first six pandemics differ genetically by many single nucleotide polymorphisms and the acquisition of two large genetic islands called Vibrio seventh pandemic islands I and II (VSP-I and VSP-II). The VSP-I island encodes eleven genes, including dncV which encodes a dinucleotide cyclase enzyme that produces the cyclic- GMP-AMP (cGAMP) molecule. Virulence studies in the infant mice model of infection revealed that dncV is the only gene in VSP-I, that when mutated, has a competitive disadvantage compared to the parental strain. This provides strong evidence that DncV and cGAMP is important for virulence. How cGAMP regulated downstream pathways to enhance virulence remained unresolved. Recently, a study revealed that another gene in VSP-I called capV, that is immediately adjacent to dncV, encodes a phospholipase that is activated by binding to cGAMP. These results suggest that cGAMP acts on the cell by binding protein receptors in a manner similar in concept of other cyclic dinucleotides. While the discover of CapV explained the effect of DncV and cGAMP on lipid metabolism in V. cholerae, the effect of cGAMP on virulence, MSHA expression and chemotaxis expression are unexplained. This proposal hypothesizes that additional protein receptor(s) bind directly to cGAMP to mediate downstream regulation of MSHA, chemotaxis and pathogenesis. We will test our hypothesis by using biochemical and genetic approaches including: Aim 1. Identifying interacting proteins of cGAMP and Aim 2. Characterizing cGAMP down regulation of the MSHA operons. Together, results from the completion of this aim will reveal how cGAMP signaling occurs in V. cholerae and shed light on the intersection between cGAMP and cyclic-di-GMP (c-di-GMP), another cyclic dinucleotide molecule also used by V. cholerae. In addition, revealing the network of signaling molecules in V. cholerae will allow better understand of pathogens can adapt when they acquire cGAMP signaling via horizontal gene transfer.

抽象的 霍乱弧菌是一种能够引起世界范围内大流行的病原体，其中包括七种 科学记录。第七次大流行埃尔托生物型取代了经典生物型 造成前六次大流行的生物型在遗传上因许多单一因素而不同 核苷酸多态性和获得两个称为第七弧菌的大型基因岛 大流行岛屿 I 和 II（VSP-I 和 VSP-II）。 VSP-I岛编码11个基因， 包括 dncV，它编码产生环化的二核苷酸环化酶。 GMP-AMP (cGAMP) 分子。幼年小鼠感染模型的毒力研究揭示 dncV 是 VSP-I 中唯一的基因，当突变时，具有竞争劣势 与亲本菌株相比。这有力地证明了 DncV 和 cGAMP 是 对于毒力很重要。 cGAMP如何调节下游途径以增强毒力 仍未解决。最近，一项研究揭示了VSP-I中的另一个基因称为capV，即 紧邻 dncV，编码一种磷脂酶，通过结合来激活 cGAMP。这些结果表明 cGAMP 通过结合蛋白受体来作用于细胞 与其他环状二核苷酸的概念类似的方式。虽然 CapV 的发现 解释了 DncV 和 cGAMP 对霍乱弧菌脂质代谢的影响， cGAMP 对毒力、MSHA 表达和趋化性表达的影响尚不清楚。这 该提案假设额外的蛋白质受体直接与 cGAMP 结合以介导 MSHA、趋化性和发病机制的下游调节。我们将检验我们的假设 通过使用生化和遗传学方法，包括： 目标 1. 识别相互作用 cGAMP 和 Aim 2 的蛋白质。表征 MSHA 的 cGAMP 下调 操纵子。总之，完成这一目标的结果将揭示 cGAMP 信号传导如何 发生在霍乱弧菌中，揭示了 cGAMP 和环二 GMP 之间的交叉点 (c-di-GMP)，霍乱弧菌也使用的另一种环状二核苷酸分子。此外， 揭示霍乱弧菌中的信号分子网络将有助于更好地理解 当病原体通过水平基因转移获得 cGAMP 信号时，它们可以适应。