Understanding the role of N, a TIR-NB-LRR protein, in plant innate immunity

描述(申请人提供)：我们的目标是了解植物抗性(R)蛋白介导先天免疫信号的分子机制。我们将继续使用N抗性基因与烟草花叶病毒(TMV)之间的互作作为模式系统。N蛋白是TIR-NB-LRR家族R蛋白的成员，被认为能特异性识别TMV复制酶蛋白的50 kDa解旋酶结构域(TMV-p50)，从而触发天然免疫反应的诱导。我们将结合遗传、分子、生化和细胞方法来了解N在先天免疫中的作用。我们将确定N如何识别TMV-p50。我们实验室的最新证据表明，N和TMV-p50在宿主-病原菌相互作用和抗性过程中，在完整的活组织中存在一段很短的时间。然而，这种相互作用不是直接的，可能依赖于一种我们称为NTI1的N-TIR相互作用蛋白。这表明TIR结构域可能参与了TMV的识别。因此，我们将确定N的结构域(S)负责识别TMV-p50。此外，我们将表征NTI1在介导N和TMV-p50关联中的作用。为了表征TMV-p50识别复合体，我们将分离和鉴定N和第n个蛋白质复合体的成分。我们实验室的最新结果表明，N与一种我们称为TFN5的转录因子直接相关。因此，N除了参与病原体识别外，还可能直接控制下游转录事件。我们将在体内测定TMV感染前后N和TFN5的相互作用动力学。我们将在先天免疫反应中识别和表征TFN5靶标。未来50年，世界人口将从60亿增加到120亿，这将产生对食品、纤维、燃料和药品的更大需求。因此，我们需要增加对植物基因的了解，以便操纵它们来设计改良作物。全世界每年因疾病造成的农作物生产力损失超过1000亿美元。因此，利用天然的R基因和其他在抗性信号通路中起作用的细胞基因来控制病原菌引起的疾病可能会带来巨大的好处。这种对内生基因的操纵将对较贫穷的公民产生重大的积极影响。它将通过提供使用杀虫剂的替代方案来服务于环境，以预防疾病，从而预防健康风险。

DESCRIPTION (provided by applicant): Our goal is to understand the molecular mechanisms by which plant resistance (R) proteins mediate innate immune signaling. We will continue to use the interaction between the N resistance gene and tobacco mosaic virus (TMV) as a model system. The N protein is a member of the TIR-NB-LRR family of R proteins and is hypothesized to specifically recognize the 50 kDa helicase domain (TMV-p50) of the TMV replicase protein to trigger induction of innate immune responses. We will use a combination of genetic, molecular, biochemical and cellular approaches to understand the function of N in innate immunity. We will determine how N recognizes TMV-p50. Recent evidence from our laboratory indicates that N and TMV-p50 associate in intact, living tissue in a narrow period over the course of the host-pathogen interaction and resistance. However, this interaction is not direct and may be dependent on an N-TIR interacting protein we call NTI1. This suggests that the TIR domain might be involved in TMV recognition. We will therefore determine domain(s) of N responsible for recognition of TMV-p50. Further, we will characterize the role of NTI1 in mediating the N and TMV-p50 association. To characterize TMV-p50 recognition complex, we will isolate and identify components of N and NTH protein complexes. Recent results from our laboratory indicate that N associates directly with a transcription factor we call TFN5. Thus, N, in addition to being involved in pathogen recognition, may also directly control downstream transcriptional events. We will determine, in vivo, the interaction dynamics of N and TFN5 before and after TMV infection. We will identify and characterize TFN5 targets during the innate immune response. An increasing world population, from 6 to 12 billion, in the next 50 years will create greater demand for food, fiber, fuel and Pharmaceuticals. We therefore need increased knowledge of plant genes in order to manipulate them to engineer improved crops. Worldwide annual losses of crop productivity due to diseases are valued over $100 billion. Therefore, control of pathogen-induced diseases using natural R genes and other cellular genes that function in the resistance signaling pathways may provide tremendous benefits. This manipulation of endogenous genes will have significant positive impact on poorer citizens. It will serve the environment by offering an alternative to pesticide use to prevent diseases and thus health risks.