Dissection of subcellular sites of NLR function during immune signaling

免疫信号传导过程中 NLR 功能亚细胞位点的剖析

• 批准号: 1354434
• 负责人: Savithramma Dinesh-Kumar
• 金额: $ 76.4万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-15 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1354434&HistoricalAwards=false
• 关键词: Dissection; subcellular; sites; NLR; function

Resistance proteins (R-proteins) are key players in a plant's defensive repertoire against pathogenic microbes. R-proteins act as sentinels that recognize incursion by a pathogen and initiate responses to limit the extent of infection. Although we understand in some detail the nature of the initial recognition event, little is known about how R-proteins signal to the plant that defenses need to be deployed. This project follows the intriguing observation that at least some R-proteins, once activated by a pathogen, interact with other proteins to stimulate enhanced expression of genes required to mount an effective immune response. The research to be carried out seeks to enhance our understanding of the molecular mechanisms that mediate these events. The results are likely to contribute new strategies for developing crop varieties that are resistant to economically significant plant diseases. The project will provide training for a postdoctoral researcher and a graduate student. Undergraduate students from under-represented minorities and economically disadvantaged students from the Biology Undergraduate Scholars Program (BUSP) will be trained. The project will also teach and train a high school student from Young Scholar Program (YSP) at UC Davis. The project will organize a science field trip for 5th grade students from an Elementary School to UC Davis.In plants and animals, the Nucleotide-binding domain and Leucine-rich Repeat (NLR) class of intracellular immune receptors function in defense against pathogens. Despite extensive research, post-pathogen recognition events leading to NLR activation and induction of defense signaling remain elusive. The investigators recent results indicate that the plant NLR N associates with the SPL6 protein in the nucleus to activate successful immune response against Tobacco Mosaic Virus (TMV). SPL6 is also required for NLR RPS4-mediated defense against Pseudomonas syringae bacteria expressing AvrRps4 effector. Therefore, SPL6 appears to be a conserved nuclear component that acts as a bridge between an activated NLR and induction of defense genes. In this project, the investigators will use a combination of genetic, molecular, biochemical, genomics, proteomics, and cell biology based approaches to understand the subcellular dynamics of NLRs during immune signaling. Precise function of SPL6 during immune signaling will be determined by identification and characterization of direct target genes that are regulated by SPL6. Also SPL6 interacting proteins will be identified and characterized. Results from the project will advance the field of immunity by providing mechanistic insights into NLRs function especially with respect to their spatial distribution and dynamics during defense. Knowledge gained will improve our understanding of plant immunity, help harness it to aid in the development of pathogen resistant crops and promote food security.

抗性蛋白（R 蛋白）是植物防御病原微生物的关键角色。 R 蛋白充当哨兵，识别病原体的入侵并启动反应以限制感染程度。尽管我们对初始识别事件的性质有一定的了解，但我们对 R 蛋白如何向植物发出需要部署防御的信号知之甚少。该项目遵循了一个有趣的观察结果，即至少一些 R 蛋白一旦被病原体激活，就会与其他蛋白相互作用，刺激增强有效免疫反应所需的基因表达。将要进行的研究旨在增强我们对介导这些事件的分子机制的理解。这些结果可能会为开发能够抵抗经济上重大植物病害的作物品种提供新的策略。该项目将为一名博士后研究员和一名研究生提供培训。来自代表性不足的少数族裔的本科生和来自生物学本科学者计划（BUSP）的经济困难学生将接受培训。该项目还将教授和培训加州大学戴维斯分校青年学者计划（YSP）的一名高中生。该项目将为小学五年级学生组织一次前往加州大学戴维斯分校的科学实地考察。在植物和动物中，细胞内免疫受体的核苷酸结合域和富含亮氨酸重复序列 (NLR) 类具有防御病原体的功能。尽管进行了广泛的研究，但导致 NLR 激活和防御信号诱导的病原体识别后事件仍然难以捉摸。研究人员最近的结果表明，植物 NLR N 与细胞核中的 SPL6 蛋白结合，可成功激活针对烟草花叶病毒 (TMV) 的免疫反应。 SPL6 也是 NLR RPS4 介导的针对表达 AvrRps4 效应子的丁香假单胞菌的防御所必需的。因此，SPL6 似乎是一种保守的核成分，充当激活的 NLR 和诱导防御基因之间的桥梁。在这个项目中，研究人员将结合遗传、分子、生化、基因组学、蛋白质组学和细胞生物学的方法来了解免疫信号传导过程中 NLR 的亚细胞动力学。 SPL6 在免疫信号传导过程中的精确功能将通过受 SPL6 调节的直接靶基因的识别和表征来确定。 SPL6 相互作用蛋白也将被鉴定和表征。该项目的结果将通过提供对 NLR 功能的机制见解，特别是在防御过程中的空间分布和动态方面，推动免疫领域的发展。获得的知识将提高我们对植物免疫力的了解，有助于利用它来帮助开发抗病原体作物并促进粮食安全。