Molecular Basis of NLR-Mediated Innate Immunity in Arabidopsis thaliana

描述(申请人提供)：这个项目的长期目标是阐明植物对细菌病原体的天然免疫的分子基础。在这一应用中，将开展实验以阐明拟南芥中NLR类天然免疫受体识别细菌病原体的分子基础。这些研究的一个主要目的是识别和表征由NLR蛋白激活引起的下游信号事件。NLR蛋白家族的免疫受体最初在植物中被描述为控制植物抗病的主要抗病(R)蛋白。随后，人们发现这类蛋白质在动物中也作为先天免疫受体发挥作用，到目前为止已经描述了20多种。我们的研究将集中在NDR1和RIN4蛋白在PAMP和效应器触发的免疫中的作用。我们最近的研究结果表明，NDR1蛋白对flg22诱导的先天免疫和RPS2信号转导通路均有影响。有趣的是，NDR1与LEA14蛋白共享蛋白质折叠和预测的3D结构，LEA14蛋白已被证明参与非生物应激反应。预测的NDR1的三维结构将使我们能够通过突变预测参与功能的氨基酸来进行结构和功能分析，并将使我们能够确定NDR1在免疫受体定位和信号转导中所起的作用。此外，我们建议研究与拟南芥RIN4蛋白对RPS2蛋白的负调控以及随后激活AvrRpt2效应蛋白相关的分子事件。一旦RPS2蛋白被激活，这一应用程序将通过使用下一代Illumina测序技术结合一个全面的酵母一杂交库来识别和表征激活的RPS2蛋白的直接靶标，该文库代表了迄今为止在拟南芥中已知的所有转录因子。为了实现这些目标，实验方法将被设计为使用生化、遗传学、细胞、蛋白质组和功能基因组学方法的组合来表征在该模型病理系统中控制抗病表达的信号转导事件。

DESCRIPTION (provided by applicant): The long-term objectives of this project are to elucidate the molecular basis of plant innate immunity in response to bacterial pathogens. In this application, experiments will be carried out to elucidate the molecular basis of bacterial pathogen recognition by the NLR class of innate immune receptors in Arabidopsis thaliana. A major aim of these studies is the identification and characterization of the downstream signaling events that result from the activation of NLR proteins. The NLR protein family of immune receptors was originally described in plants as the major class of disease resistance (R) proteins that control disease resistance in plants. Subsequently, it was discovered that this class of protein also functions in animals as innate immune receptors as more than twenty have been described to date. Our research will focus on the role of the NDR1 and RIN4 proteins in both PAMP and effector-triggered immunity. Our recent results have revealed that NDR1 protein compromises both flg22-induced innate immunity and the RPS2 signal transduction pathway. Interestingly, the NDR1 shares protein folds and a predicted 3-D structure with the LEA14 protein that has been shown to be involved in abiotic stress responses. The predicted 3-D structure of NDR1 will allow us to perform a structure and function analysis by mutating amino acids that are predicted to be involved function and will allow us to ascertain the role NDR1 plays in immune receptor location and signal transduction. Furthermore, we propose to study the molecular events associated with the negative regulation of the RPS2 protein by the Arabidopsis RIN4 protein and the subsequent activation the AvrRpt2 effector protein. Once the RPS2 protein is activated, this application will identify and characterize the direct targets of the activated RPS2 protein by employing next-generation Illumina sequencing technologies in conjunction with a comprehensive yeast-one hybrid library that represents all the transcription factors known to date in Arabidopsis. To accomplish these goals, experimental approaches will be designed to employ a combination of biochemical, genetic, cellular, proteomic and functional genomic approaches to characterize the signal transduction events controlling the expression of disease resistance in this model pathosystem.