The Effect of the Pseudomonas Syringae Protein HopPsyA (HrmA) on Plants

丁香假单胞菌蛋白 HopPsyA (HrmA) 对植物的影响

• 批准号: 9983113
• 负责人: James Alfano
• 金额: $ 33万
• 依托单位: University of Nevada Las Vegas
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2000-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9983113&HistoricalAwards=false
• 关键词: Effect; Pseudomonas; Syringae; Protein; HopPsyA

To date, researchers studying proteins that travel the type III (Hrp) protein secretion system of bacterial plant pathogens do not know any of the virulence targets of these proteins - the bacterial-intended target that presumably contributes to the ability of these bacteria to be pathogenic. The experiments described in this proposal are designed to reveal the virulence target of HopPsyA (formally known as HrmA). HopPsyA is a protein that travels the type III (Hrp) secretion pathway of the plant pathogen Pseudomonas syringae and, based on indirect evidence, appears to be delivered into plant cells. On some plants, HopPsyA functions as an avirulence (Avr) protein and induces a rapid defense response. By focussing on plants that do not recognize HopPsyA by mounting a defense response, the researchers hope to identify HopPsyA's plant target to begin to unravel how Hrp-delivered proteins allow pathogenic bacteria to multiply and cause disease in plants. Yeast 2-hybrid data presented in this proposal suggest that HopPsyA targets the Mad2 protein in Arabidopsis. Mad2 is a conserved protein in eucaryotes that plays an important role in the cell cycle. When eucaryotic cells have damaged spindles during metaphase, a checkpoint, called the spindle checkpoint, stalls the cell cycle so the cells do not continue into anaphase. This helps prevent daughter cells from receiving too many or too few chromosomes during segregation. Mad2 plays a central role in the spindle checkpoint. Intriguingly, if HopPsyA does indeed interact with Mad2, this suggests that bacterial plant pathogens may be capable of modifying the plant cell cycle to improve the likelihood of successful pathogenesis. The proposed work will encompass many different molecular and cell biological techniques including standard light microscopy, yeast 2-hybrid screens, PCR mutagenesis, protein separation and immunoblot analysis, experiments with transgenic plants, coimmunoprecipitation and other methods to detect protein-protein interactions. Many components between the type III systems in pathogens of animal and plants are conserved. The research described in this proposal should provide important information about type III secretion systems and be of broad interest to researchers studying host-microbe interactions.

迄今为止，研究细菌植物病原体的III型（Hrp）蛋白分泌系统的蛋白质的研究人员不知道这些蛋白质的任何毒力靶标-细菌预期的靶标可能有助于这些细菌的致病能力。本提案中描述的实验旨在揭示HopPsyA（正式称为HrmA）的毒力靶标。HopPsyA是一种蛋白质，其行进植物病原体假单胞菌的III型（Hrp）分泌途径，并且基于间接证据，似乎被递送到植物细胞中。在一些植物中，HopPsyA作为无毒（Avr）蛋白发挥作用，并诱导快速的防御反应。通过关注那些通过建立防御反应而不识别HopPsyA的植物，研究人员希望确定HopPsyA的植物靶标，从而开始揭示Hrp传递的蛋白质如何允许病原菌繁殖并在植物中引起疾病。酵母双杂交的数据表明，HopPsyA的目标是在拟南芥Mad 2蛋白。Mad 2是真核生物中的保守蛋白，在细胞周期中起重要作用。当真核细胞在中期有损坏的纺锤体时，一个被称为纺锤体检查点的检查点会使细胞周期停滞，使细胞不能继续进入后期。这有助于防止子细胞在分离过程中接收过多或过少的染色体。Mad 2在纺锤体检查点中起核心作用。有趣的是，如果HopPsyA确实与Mad 2相互作用，这表明细菌性植物病原体可能能够改变植物细胞周期，以提高成功发病的可能性。 拟议的工作将包括许多不同的分子和细胞生物学技术，包括标准光学显微镜，酵母双杂交筛选，PCR诱变，蛋白质分离和免疫印迹分析，转基因植物实验，免疫共沉淀和其他方法来检测蛋白质-蛋白质相互作用。动植物病原体中的许多III型系统之间的组分是保守的。本提案中描述的研究应提供有关III型分泌系统的重要信息，并对研究宿主-微生物相互作用的研究人员具有广泛的兴趣。