Quorum-sensing mediated communication between pandemic Vibrio cholerae and phage VP882

项目摘要/摘要 细菌在自然栖息地被称为噬菌体的感染病毒轰炸。在感染宿主时，噬菌体 必须采取两种生活方式中的一种：溶原性，即噬菌体留在宿主体内并向下传递 后代，或噬菌体复制的裂解，杀死宿主，并传播到新的细胞。噬菌体一直被认为是 从溶源向裂解的转变完全是为了对宿主的胁迫和DNA损伤作出反应。来自以下方面的新研究 巴斯勒实验室发现，噬菌体可以监测宿主通信分子，称为 自动诱导器。在一个称为群体感应的过程中，细菌产生、释放和检测自动诱导剂，并在 响应，协调群体行为。群体感应反应噬菌体检测宿主产生的自体诱导物 并利用他们获得的信息来推动他们从裂解到溶源的生活方式转变。这些最新的发现 让我来了解噬菌体是如何操纵细菌宿主的，以及对宿主、多菌体和 宿主是其成员的物种细菌群落，以及所有实体都在其中的真核宿主 住下来。我研究的首要目标是定义噬弧菌之间的跨域交流 VP882--第一个在群体感应上发现“窃听”的噬菌体及其宿主--全球病原菌弧菌 霍乱弧菌，启动噬菌体裂解循环。使用遗传、生化和结构的组合 方法，我将确定这种宿主-噬菌体化学通信背后的分子机制 进程。首先，我将从巴斯勒实验室的专家那里学习细菌遗传学的技能，并进行一次 筛选出群体感应诱导的噬菌体裂解循环的抑制子。第二，我会用生化的 定量描述法定人数中两个关键信号组件之间相互作用的方法- 感应诱导的噬菌体裂解途径。最后，我将依靠我在结构生物学方面的背景来解决 这些相同的信号组件的结构，单独的和复杂的，实现原子级的分辨率 了解噬菌体经历生活方式转变所需的相互作用。理想的结果是 我的研究是对域间化学通信的机械性理解，以及 噬菌体疗法的发展。磨练我在细菌遗传学、蛋白质生物化学和 在我博士后的培训过程中，大分子结晶学将使我能够推出一种 在一流研究机构的独立研究项目。

PROJECT SUMMARY/ABSTRACT Bacteria are bombarded by infecting viruses, called phages, in natural habitats. Upon infection of a host, phages must undertake one of two lifestyles: lysogeny where the phage remains in the host and is passed down to offspring, or lysis where the phage replicates, kills the host, and spreads to new cells. Phages have been thought to transition from lysogeny to lysis exclusively in response to host stress and DNA damage. New research from the Bassler laboratory has revealed that phages can monitor host communication molecules, called autoinducers. In a process called quorum sensing, bacteria produce, release, and detect autoinducers, and in response, orchestrate group behaviors. Quorum-sensing-responsive phages detect host-produced autoinducers and exploit the information they garner to drive their lysis-lysogeny lifestyle transitions. These recent findings position me to discover how phages manipulate bacterial hosts and the consequences to the host, to the multi- species bacterial community of which the host is a member, and to the eukaryotic host in which all the entities reside. The overarching goal of my research is to define how cross-domain communication between vibriophage VP882, the first phage discovered to “eavesdrop” on quorum sensing, and its host, the global pathogen Vibrio cholerae, launches the phage lytic cycle. Using a combination of genetic, biochemical, and structural approaches, I will identify the molecular mechanisms underlying this host-phage chemical communication process. First, I will learn skills in bacterial genetics from experts in the Bassler laboratory and conduct a genetic screen to identify the repressor of the quorum-sensing-induced phage lytic cycle. Second, I will use biochemical methods to quantitatively characterize interactions between two key signaling components in the quorum- sensing-induced phage lysis pathway. Lastly, I will rely on my background in structural biology to solve the structures of these same signaling components, individually and in complex, enabling atomic-level-resolution understanding of the interactions required for the phage to undergo lifestyle transitions. The ideal outcomes of my research are a mechanistic understanding of inter-domain chemical communication and new possibilities for development of phage therapies. Honing my skills in bacterial genetics, protein biochemistry, and macromolecular crystallography over the course of my postdoctoral training will enable me to launch an independent research program at a top-tier research institution.