Quorum sensing regulation of bacterial development

项目摘要 细菌使用称为群体感应的细胞-细胞信号系统进行交流，集体改变 基因表达对种群密度和组成变化的反应。仲裁感应控制 有利于群体适应和生存的行为，包括生物膜的形成，运动性， 生物发光，毒素的产生和分泌。更全面地了解细胞-细胞如何 信号调节毒力并影响环境中的细菌可导致 调节群体感应以减轻发病机制的抗微生物分子。尽管取得了进展，但 阐明法定信号输入，相对较少知道输出-转录 控制细菌的群体行为和发展的规章制度。建议的目标是 研究是定义细菌如何使用群体感应信号来控制毒力基因的表达，使用 弧菌作为已建立的群体感应模型系统和相关病原体。在弧菌物种中，LuxR 是主要的转录因子，也是群体感应基因和毒力的保守核心调节因子。 以前的工作确定了重要的和高度保守的生化、生物物理和遗传特征 LuxR和弧菌控制基因表达的信号系统。然而，群体感应的影响 在许多发育途径上的差异，即使在密切相关的弧菌菌株之间也是如此 是不被理解的。拟议的研究将在这些发现的基础上扩展，通过以下方式检查基因调控 然后更广泛地将这些信息与守恒和影响联系起来 弧菌物种间的法定信号网络。首先，拟议的研究将确定 基于ESTED的染色体空间组织与LuxR调控的关系 类核结构蛋白对几种弧菌群体感应基因表达的影响 物种。第二，更广泛地研究来自“自我”(群体感应自动感应器)的信号的影响。 和其他(环境)，群体感应基因的表达将在单细胞和群体中进行评估- 对自动诱导物信号和养分利用率的变化作出反应的广泛水平。建议数 微流体、细胞培养和宿主感染实验与比较基因组学相结合将提供关键 群体感应信号与弧菌对环境和宿主信号的适应之间的联系。第三， Van Kessel实验室最近开发出专门阻断LuxR蛋白功能的噻吩磺酰胺抑制剂 在弧菌中。这些分子是指导我们理解LuxR功能和信息的关键工具 潜在治疗化合物的结构-活性建模和抑制剂设计。总的来说，建议的 研究将提供对理解法定信号及其如何影响细菌至关重要的基础数据 致病机制有助于弧菌病治疗的未来进展。

Project Summary Bacteria communicate using the cell-cell signaling system called quorum sensing to collectively alter gene expression in response to changes in population density and composition. Quorum sensing controls behaviors that benefit the group for adaption and survival, including biofilm formation, motility, bioluminescence, and toxin production and secretion. A more comprehensive understanding of how cell-cell signaling regulates virulence and impacts bacteria in their environmental niches can lead to the development of anti-microbial molecules that modulate quorum sensing to mitigate pathogenesis. Despite advances in elucidating the quorum signaling inputs, comparatively less is known about the output – the transcriptional regulation program that controls group behaviors and development in bacteria. The objective of the proposed research is to define how bacteria use quorum sensing signaling to control virulence gene expression, using Vibrio bacteria as established quorum sensing model systems and relevant pathogens. In Vibrio species, LuxR is the master transcription factor and the conserved core regulator of quorum sensing genes and virulence. Previous work identified important and highly conserved biochemical, biophysical, and genetic features of LuxR and Vibrio quorum signaling systems that govern gene expression. Yet, the influence of quorum sensing on numerous developmental pathways varies even among closely related Vibrio strains through means that are not understood. The proposed research will expand upon these findings to examine gene regulation by LuxR at the mechanistic level and then more broadly connect this information to the conservation and impact of quorum signaling networks across Vibrio species. First, the proposed research will determine the connections between spatial organization of the chromosome and LuxR regulation based on established findings that nucleoid structuring proteins impinge on quorum sensing gene expression in several Vibrio species. Second, to more broadly examine the influence of signals from “self” (quorum sensing autoinducers) and “other” (environment), quorum sensing gene expression will be assessed at the single-cell and population- wide level in response to variations in autoinducer signaling and nutrient availability. The proposed microfluidics, cell culture, and host infection experiments combined with comparative genomics will provide key links between quorum sensing signaling and Vibrio adaptation to environmental and host signals. Third, the van Kessel lab recently developed thiophenesulfonamide inhibitors that specifically block LuxR protein function in Vibrio bacteria. These molecules are key tools that will guide our understanding of LuxR function and inform structure-activity modeling and inhibitor design for potential therapeutic compounds. Collectively, the proposed research will provide fundamental data critical to understanding quorum signaling and how it impacts bacterial pathogenesis to contribute to future advances in vibriosis disease treatment.