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

我们的目标是了解植物抗性（R）蛋白介导先天性抗病性的分子机制。 免疫信号我们将继续利用抗氮基因与烟草的互作 花叶病毒（TMV）作为模型系统。N蛋白是R蛋白TIR-NB-LRR家族的成员 并被假设特异性识别TMV复制酶的50 kDa解旋酶结构域（TMV-p50 蛋白质来触发先天免疫应答的诱导。我们将结合基因，分子， 生物化学和细胞的方法来了解N在先天免疫中的功能。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相关， 完整的，活的组织在一个狭窄的时期内经历了宿主-病原体的相互作用和抵抗。 然而，这种相互作用不是直接的，可能依赖于一种我们称为NTH的N-TIR相互作用蛋白。 这表明TIR结构域可能参与TMV的识别。因此我们将决定 负责识别TMV-p50的N结构域。此外，我们将描述NTH的作用， 介导N和TMV-p50的关联。为了表征TMV-p50识别复合物，我们将分离 并鉴定N和NTH蛋白复合物的组分。我们实验室最近的结果表明， 与我们称之为TFN 5的转录因子直接相关因此，N除了参与病原体 识别，也可以直接控制下游转录事件。我们将在体内确定 TMV侵染前后N和TFN 5的互作动态我们将鉴定和表征TFN 5 在先天免疫反应中的作用。 今后50年，世界人口将从60亿增加到120亿，这将产生更大的粮食需求， 纤维、燃料和药品。因此，我们需要增加对植物基因的了解， 操纵它们来改良作物。全球每年因病害造成的作物产量损失 价值超过一千亿美元因此，使用天然R基因和 在抗性信号传导途径中起作用的其它细胞基因可提供巨大的益处。 这种对内源基因的操纵将对较贫穷的公民产生重大的积极影响。它将服务于 通过提供替代杀虫剂的方法来预防疾病和健康风险，从而保护环境。

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 NTH. 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 NTH 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.