Diversity and evolution of P syringae type III effectors

丁香假单胞菌III型效应子的多样性和进化

• 批准号: 6730041
• 负责人: JEFFERY L. DANGL
• 金额: $ 28.87万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6730041
• 关键词: Arabidopsis; Pseudomonas; bacteria infection mechanism; bacterial genetics; bacterial proteins; biochemical evolution; bioinformatics; flow cytometry; functional /structural genomics; gene induction /repression; genetic models; genetic promoter element; genetic screening; green fluorescent proteins; high throughput technology; host organism interaction; molecular cloning; nucleic acid sequence; open reading frames; operon; pathologic process; phenotype; protein structure function; transcription factor; virulence

DESCRIPTION (provided by applicant): Identification of virulence factors is a necessary first step to study the mechanisms and evolution of pathogenicity. We propose to compare the type III disease effector proteins from a phylogenetically diverse set of plant pathogenic Pseudomonads chosen to represent the most broad distribution of the species possible. P. syringae is an ideal model organism to study the distribution and evolution of type III effectors. Type III effectors interact with cellular host targets, and modulate host defense responses or metabolism in a manner conducive to pathogen proliferation. Most of the P. syringae effectors have not yet been characterized, and we remain naive as to the collective diversity of host cellular functions they manipulate. Although the functions of P. syringae effector proteins during disease remain poorly understood, they can often be monitored via their phenotypes following in planta expression of a given type III effector. Bacterial pathogens of both animals, such as Salmonella spp., Yersinia spp., Shigella spp. and pathogenic E. coli also rely on type III secretion systems for pathogenesis. Thus, our results will inform studies of these bacteria and their animal hosts, including humans. Because P. syringae is pathogenic on a variety of distantly related plant hosts, many of which can be genetically manipulated, our system has advantages over models of type III pathogenesis of animals, which generally focus only on strains pathogenic on phylogenetically related mammalian hosts. We have devised and implemented a high throughput Fluorescence Activated Cell Sorter (FACS) based experimental approach to capture all of the type III effectors from the genome of any given P. syringae isolate. We chose 13 P syringae isolates that are pathogens of an evolutionarily diverse set of host plants. We intend to sieve through these 13 genomes to describe their suites of type III effectors. We further intend to begin dissection of their effects on host cell biology, using the easily manipulated Arabidopsis plant as a model where appropriate. This proposal is highly interdisciplinary, drawing on methodologies and expertise in microbiology, bioinformatics and plant-pathogen interactions in conjunction with high throughput bacterial cell sorting using the FACS. Our work will broadly impact the understanding of a widely distributed pathogenicity mechanism that affects both human health and agriculture. Additionally, our work may have relevance in biodefense with respect to basic understanding of pathogenesis in bacteria that can potentially be weaponized.

描述(由申请人提供)： 毒力因子的鉴定是研究致病机理和进化的必要的第一步。我们建议比较一组系统发育不同的植物致病假单胞菌的III型疾病效应蛋白，这些假单胞菌被选择来代表物种可能最广泛的分布。丁香假单胞菌是研究III型效应器分布和进化的理想模式生物。III型效应器与细胞宿主靶标相互作用，以有利于病原体增殖的方式调节宿主防御反应或新陈代谢。大多数丁香疫霉菌的效应器还没有被定性，我们对它们操纵的宿主细胞功能的集体多样性仍然很天真。尽管对丁香疫霉效应蛋白在疾病中的功能仍知之甚少，但通常可以通过它们在给定的III型效应器的植物表达后的表型来监测它们。 沙门氏菌、耶尔森氏菌、志贺氏菌等。致病性大肠杆菌也依赖于III型分泌系统来致病。因此，我们的结果将为这些细菌及其动物宿主(包括人类)的研究提供信息。由于丁香疫霉菌在多种远缘关系的植物宿主上是致病的，其中许多是可以通过遗传操作的，因此我们的系统比动物III型致病模型具有优势，后者通常只关注在系统发育相关的哺乳动物宿主上致病的菌株。 我们设计并实现了一种基于高通量荧光激活细胞分类器(FACS)的实验方法，可以从任何给定的丁香疫霉分离株的基因组中捕获所有III型效应器。我们选择了13个丁香菌分离物，这些分离物是一组进化上不同的寄主植物的病原体。我们打算筛选这13个基因组，以描述它们的III型效应器套件。我们进一步打算开始剖析它们对宿主细胞生物学的影响，在适当的地方使用容易操纵的拟南芥植物作为模型。 这项建议是高度跨学科的，利用微生物学、生物信息学和植物-病原体相互作用的方法和专业知识，以及使用FACS的高通量细菌细胞分选。 我们的工作将广泛影响对广泛分布的影响人类健康和农业的致病机制的理解。此外，我们的工作可能在生物防御方面具有相关性，涉及到对细菌致病机制的基本理解，这些致病机制可能会被武器化。