MODULATION OF NF-KB SIGNALLING BY E COLI PROTEIN KINASES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 肠出血性大肠杆菌(EHEC)O157：H7对食源性疾病造成巨大的经济和健康负担。肠出血性大肠杆菌III型分泌系统(T3S)效应蛋白调节宿主信号通路的机制尚不完全清楚。该项目将具有重要意义，因为它将定义EHEC效应蛋白NleH1和NleH2扰乱正常宿主对细菌感染的先天性免疫反应的机制。这项研究的中心假设是，NleH蛋白与核因子-kappaB亚单位RPS3结合，扰乱宿主对细菌感染的特定转录反应。我们将测试我们的中心假设，并通过追求以下具体目标来实现此应用程序的总体目标： 目的1.定位NleH-RPS3结合域。我们的工作假设是NleH1和NleH2与哺乳动物的NF-kappaB亚单位RPS3结合，颠覆其正常功能。 目的2.量化NleH1和NleH2易位对宿主转录的影响。我们的工作假设是，NleH1抑制依赖于NF-kappaB的宿主转录，而NleH2刺激NF-kappaB。 目的3.在附着/消除病原体的动物模型中，测定NleH1和NleH2对细菌毒力的贡献。我们的工作假设是，NleH1和NleH2通过在细菌定植和宿主炎症反应之间保持最佳平衡来促进细菌传播。 这项拟议的研究具有创新性，因为它将检验这样一种假说，即移位的细菌蛋白激酶通过破坏选定的宿主对外部刺激的转录反应的新的分子说明子来颠覆宿主对感染的固有反应。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Enterohemorrhagic E. coli (EHEC) O157:H7 contributes greatly to the enormous economic and health burden of food borne disease. The mechanisms by which EHEC Type III Secretion System (T3S) effector proteins modulate host signaling pathways are incompletely characterized. This project will be significant because it will define the mechanism by which the EHEC effector proteins NleH1 and NleH2 disrupt the normal host innate immune response to bacterial infection. The central hypothesis for the proposed research is that NleH proteins bind to the NF-kappaB subunit RPS3 to disrupt specific host transcriptional responses to bacterial infection. We will test our central hypothesis and accomplish the overall objective of this application by pursuing the following specific aims: Aim 1. Map the NleH-RPS3 binding domains. Our working hypothesis is that NleH1 and NleH2 bind the mammalian NF-kappaB subunit RPS3 to subvert its normal function. Aim 2. Quantify the influence of NleH1 and NleH2 translocation on host transcription. Our working hypothesis is that NleH1 represses NF-kappaB-dependent host transcription, whereas NleH2 stimulates NF-kappaB. Aim 3. Measure the contribution of NleH1 and NleH2 to bacterial virulence in animal models of attaching/effacing pathogens. Our working hypothesis is that NleH1 and NleH2 promote bacterial transmission by maintaining an optimal balance between bacterial colonization vs. host inflammatory responses. The proposed research is innovative because it will test the hypothesis that translocated bacterial protein kinases subvert the host innate response to infection by disrupting a novel molecular specifier of selected host transcriptional responses to external stimuli.