Activation of immune receptor signaling by a sulfated peptide

酪氨酸硫酸化是一种重要的翻译后修饰， 显示显著影响受体/配体相互作用并调节疾病 植物和动物的结果。尽管它的重要性，酪氨酸的确切作用， 在蛋白质功能、宿主受体活化和感染中的硫酸化作用还不清楚。 这项提案的长期目标是阐明酪氨酸 硫酸化影响受体-配体相互作用和对感染的抗性。 作为这些研究的模型，我们将研究水稻XA 21的相互作用 免疫受体，一种代表一大类植物和动物蛋白质 免疫受体，与硫酸化微生物蛋白，RaxX-sY，这是能够触发一个 在宿主体内产生强烈的免疫反应我们提出三个相辅相成的目标： 目标1。确定控制硫酸化Raxx相互作用的关键氨基酸 宿主受体。目标2.测试RaxX-sY是否需要RaxB和CvaB 加工和分泌。目标3。确定Pald的生物学功能1 基因在先天免疫反应中的作用 拟议的分析将提供一个框架，阐明 RaxX-sY/Xa 21相互作用中的磺基酪氨酸。为了实现我们的目标，我们将 新的实验工具和方法。其中包括使用扩展的遗传密码 在大肠杆菌中生产全长硫酸化重组蛋白的方法。大肠杆菌，新的检测方法， 评估受体活化和配体结合，以及液相色谱串联 质谱联用紫外光解离，以促进 肽内硫酸化酪氨酸残基的表征。 拟议的研究预计将导致对硫酸盐的新见解 分子及其相互作用的伙伴。从这项研究中获得的信息可以 用于开发能够抑制或激活受体的基于肽的试剂， 具有高度亲和力和特异性的配体相互作用，具有潜在的应用 在研究、农业和医药方面。因为受体或配体的硫酸化是 重要的是控制严重疾病的结果，因为先天免疫是 对于植物和动物防御病原体至关重要，预期结果将是 与人类健康密切相关。

Tyrosine sulfation is an important post-translational modification that has been shown to significantly influence receptor/ligand interactions and modulate disease outcome in both plants and animals. Despite its importance, the precise role of tyrosine sulfation in protein function, host receptor activation and infection is not well understood. The long-term goal of this proposal is to elucidate the mechanisms with which tyrosine sulfation influences receptor-ligand interactions and resistance to infection. As a model for these studies, we will investigate the interaction of the rice XA21 immune receptor, a protein that is representative of a large class of plant and animal immune receptors, with the sulfated microbial protein, RaxX-sY, which is able to trigger a potent immune response in its host. We propose three complementary aims: Aim 1. Identify key amino acids that govern the interaction of sulfated RaxX with host receptors. Aim 2. Test if RaxB and CvaB are required for RaxX-sY processing and secretion. Aim 3. Determine the biological function of the Pald1 gene in the innate immune response. The proposed analyses will provide a framework for elucidating the critical role of sulfotyrosine in RaxX-sY/Xa21 interactions. To accomplish our goals, we will employ new experimental tools and approaches. These include using an expanded genetic code approach to produced full-length sulfated recombinant proteins in E. coli, new assays to assess receptor activation and ligand binding, and a liquid chromatography tandem mass spectrometry coupled with ultraviolet photodissociation to facilitate the characterization of sulfated tyrosine residues within peptides. The proposed studies are expected to lead to new insights regarding sulfated molecules and their interacting partners. The information gained from this research can be used to develop peptide-based reagents capable of inhibiting or activating receptor- ligand interactions with a high degree of affinity and specificity with potential applications in research, agriculture and medicine. Because sulfation of receptors or ligands is important in controlling the outcome of serious diseases and because innate immunity is critical for plant and animal defense against pathogens, the expected results will be broadly relevant to human health.