Protein phosphorylation and Campylobacter jejuni pathogenesis

摘要 空肠弯曲杆菌是美国和世界各地胃肠炎的主要细菌来源，有140 全世界每年有100万例空肠弯曲菌胃肠炎，美国每年有130万例空肠弯曲菌胃肠炎。这种感染会导致 每年死亡3万人，主要是不发达国家的5岁儿童。大多数C。 空肠病是零星的，由受污染的食物(尤其是家禽)和暴露在环境中引起。 沃特斯。一些空肠弯曲菌感染(~1/1000)导致格林-巴利综合征的发生，格林-巴利综合征是 引起全世界急性瘫痪，以及反应性关节炎等后遗症。尽管流行率很高 空肠弯曲杆菌的致病机制和近40年的研究 仍然没有完全被理解和严重不足的研究。 细菌调节蛋白的天冬氨酸残基的磷酸化是一种众所周知的 调节基因表达的变化。然而，人们越来越认识到蛋白质的磷酸化 在丝氨酸/苏氨酸(S/T)残基也改变蛋白质的功能。S/T磷酸化系统使用特定的 作为回应，激酶使蛋白质磷酸化，磷酸酶从S/T残基中去除磷酸盐 对环境信号的影响。重要的是，这发生在细菌病原体中，改变了许多与毒力相关的 特点。我们的初步研究首次表明，空肠弯曲菌S/T 与运动/趋化的关键致病决定因素相关的八种蛋白质磷酸化，提示 S/T磷酸化调控空肠弯曲菌毒力。我们将在C.定义S/T磷酸化系统。 空肠，根据以下假设： 总体假设：空肠弯曲菌使S/T残基上的蛋白质磷酸化，以调节运动/趋化和 相关的发病特点，通过新的S/T激酶/磷酸酶。 我们建议对空肠弯曲菌中S/T蛋白的磷酸化进行详细的研究，重点研究其机制。 运动/趋化相关蛋白的磷酸化影响它们的功能，以及决定 影响S/T磷酸化水平的蛋白质。我们将使用遗传、生化和 先进的磷酸蛋白质组学方法，以实现这两个具体目标中概述的目标：目标1。 目的1.确定S/T磷酸化对运动/趋化相关蛋白功能的影响。 确定可能的S/T激酶/磷酸酶蛋白在修饰空肠弯曲菌蛋白中的作用。加在一起，这些 将为我们确定干扰空肠弯曲菌S/T的可用药靶点的长期目标奠定基础 磷酸化和阻断宿主间的传递和人类的发病机制。

ABSTRACT Campylobacter jejuni is a primary bacterial cause of gastroenteritis in the US and throughout the world, with 140 million cases worldwide and 1.3 million cases of C. jejuni gastroenteritis in the US each year. This infection leads to >30,000 deaths annually, primarily in children <5 years old in underdeveloped countries. Most cases of C. jejuni disease are sporadic and result from contaminated food (especially poultry) and exposure to environmental waters. Some C. jejuni infections (~1/1,000) lead to the development of Guillain-Barré Syndrome, the leading cause of acute paralysis in the world, as well as reactive arthritis and other sequelae. Despite the high prevalence of Campylobacter disease and some 40 years of research, the mechanisms by which C. jejuni causes disease remain incompletely understood and severely understudied. Phosphorylation of aspartate residues of bacterial regulatory proteins is a well-known mechanism for mediating changes in gene expression. However, it is increasingly recognized that phosphorylation of proteins at serine/threonine (S/T) residues also modifies protein function. The S/T phosphorylation system uses specific kinases to phosphorylate proteins, and phosphatases to remove the phosphates from S/T residues, in response to environmental signals. Importantly, this occurs in bacterial pathogens, modifying many virulence-associated characteristics. For the first time, our preliminary studies indicate provide new evidence that C. jejuni S/T phosphorylates eight proteins related to the critical pathogenic determinants of motility/chemotaxis, suggesting that S/T phosphorylation modulates C. jejuni virulence. We will define the S/T phosphorylation system in C. jejuni, according to the following hypothesis: Overall Hypothesis: C. jejuni phosphorylates proteins at S/T residues to modulate motility/chemotaxis and related pathogenesis characteristics, by means of novel S/T kinases/phosphatases. We propose a detailed study of protein S/T phosphorylation in C. jejuni, focusing on the mechanism by which the phosphorylation of motility/chemotaxis-related proteins affects their functions, as well as determining the proteins that affect the levels of S/T phosphorylation. We will use a combination of genetic, biochemical, and advanced phosphoproteomics approaches to achieve the goals outlined in these two specific aims: Aim 1. Determine the role of S/T phosphorylation for the function of motility/chemotaxis-related proteins, and Aim 2. Determine the roles of putative S/T kinase/phosphatase proteins in modifying C. jejuni proteins. Together, these will lay the groundwork for our long-term goal of identifying druggable targets to interrupt C. jejuni S/T phosphorylation and interrupting inter-host transmission and pathogenesis in humans.