Protein phosphorylation and Campylobacter jejuni pathogenesis

摘要 空肠弯曲杆菌是美国和全世界胃肠炎的主要细菌原因， 130万例C.空肠肠胃炎在美国每年。这种感染导致 每年有超过30 000人死亡，主要是不发达国家5岁以下的儿童。大多数C. 空肠疾病是散发性，由受污染的食物（特别是家禽）和暴露于环境 沃茨。一些C。空肠感染（约1/1，000）导致发生格林-巴利综合征， 引起急性瘫痪以及反应性关节炎等后遗症。尽管患病率很高， 弯曲杆菌病的机制和大约40年的研究，C。空肠致病 仍然不完全了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机制， 介导基因表达的变化。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）残基处的修饰也改变蛋白质功能。S/T磷酸化系统使用特定的 激酶磷酸化蛋白质，磷酸酶从S/T残基中除去磷酸盐， 环境信号。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基因。 特色初步研究首次为C.空肠S/T 磷酸化与运动性/趋化性的关键致病决定因素相关的八种蛋白质，表明 S/T磷酸化调节C.空肠毒力我们将在C. 空肠，根据以下假设： 总体假设：C。空肠在S/T残基磷酸化蛋白质以调节运动性/趋化性， 相关的发病机制的特点，通过新的S/T激酶/磷酸酶。 我们提出了一个详细的研究蛋白质S/T磷酸化在C。jejuni，重点是机制， 运动性/趋化性相关蛋白的磷酸化影响其功能，以及决定 影响S/T磷酸化水平的蛋白质。我们将综合运用遗传学、生物化学和 先进的磷酸化蛋白质组学方法，以实现这两个具体目标中概述的目标：目标1。 确定S/T磷酸化对运动/趋化相关蛋白功能的作用，目的2。 确定假定的S/T激酶/磷酸酶蛋白在修饰C.空肠蛋白。所有这些 将为我们的长期目标奠定基础，即确定可药物化的目标，以中断C。空肠S/T 磷酸化和中断宿主间的传播和发病机制。

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.