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: 10614436
• 负责人: VINCENT T LEE
• 金额: $ 19.07万
• 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 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10614436
• 关键词: Bacterial Adhesins; Binding; Binding Proteins; Biochemical; Biological Assay; Blood capillaries; Cells; Characteristics; Chemotaxis; Cyclic AMP; Cyclic GMP; 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; Ligands; 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; Repression; Scanning; Signal Pathway; Signal Transduction; Signaling Molecule; Single Nucleotide Polymorphism; Small RNA; Structure; Surface; Techniques; Testing; Vibrio; Vibrio cholerae; Virulence; affinity labeling; biotypes; cellulose synthase; genetic approach; lipid metabolism; mouse model; mutant; overexpression; pandemic disease; pathogen; potassium ion; promoter; receptor; 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.

摘要 霍乱弧菌是一种病原体，能够引起世界范围的大流行， 科学记录。第七次大流行的El Tor生物型取代了经典的 导致前六次大流行的生物型在遗传上有许多不同， 核苷酸多态性和获得两个大的遗传岛称为弧菌第七 流行岛I和II（VSP-I和VSP-II）。VSP-I岛编码11个基因， 包括编码二核苷酸环化酶的dncV，该酶产生环状- GMP-AMP（cGAMP）分子。在幼鼠感染模型中进行的毒力研究显示， dncV是VSP-I中唯一的基因，当突变时， 与亲本菌株相比。这提供了强有力的证据，表明DncV和cGAMP是 重要的是毒力。cGAMP如何调节下游途径以增强毒力 仍然没有解决。最近，一项研究表明，VSP-I中的另一个基因称为capV，即 紧邻dncV，编码磷脂酶，通过结合 cGAMP。这些结果表明，cGAMP通过结合细胞中的蛋白受体而作用于细胞。 在概念上类似于其它环状二核苷酸的方式。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 一项提案假设另外的蛋白质受体直接与cGAMP结合以介导 MSHA的下游调节、趋化性和发病机制。我们将测试我们的假设 通过使用生物化学和遗传学方法，包括：目的1.识别交互 cGAMP和Aim 2蛋白。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信号传导是如何在细胞中发挥作用的。 在霍乱弧菌中发生，并阐明了cGAMP和cyclic-di-GMP之间的交叉点 （c-di-GMP），也被霍乱弧菌使用的另一种环状二核苷酸分子。此外，本发明还提供了一种方法， 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信号传导时，它们可以适应。