CAREER: Elucidating the molecular mechanism of the Vibrio cholerae Vc2 cyclic di-GMP riboswitch

职业：阐明霍乱弧菌 Vc2 环二 GMP 核糖开关的分子机制

• 批准号: 1253684
• 负责人: Christopher Waters
• 金额: $ 50万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-15 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1253684&HistoricalAwards=false
• 关键词: CAREER; Elucidating; molecular; mechanism; Vibrio

Intellectual Merit: A fundamental decision faced by all organisms is whether to colonize a given environment or migrate to new a one. For bacteria, this decision consists of transitioning between a motile state, and a sessile, biofilm forming existence. Biofilms are defined as multicellular communities of bacteria that are encased in a protective extracellular matrix. Biofilms are the predominant form of bacterial growth in nature, and allow bacteria to survive predation, toxic chemicals, and harsh conditions. Thus, biofilms represent important ecological niches in every environment and influence industrial applications such as agriculture, bioenergy and water purification. Over the last decade, it has become apparent that the intracellular signaling molecule cyclic di-GMP (c-di-GMP) plays a fundamental role in the vast majority of bacteria to control the transition between motility and biofilm formation. However, the molecular mechanisms by which c-di-GMP regulates these behaviors are not well understood. This research project will study a novel mechanism by which c-di-GMP exerts its function. In Vibrio cholerae, c-di-GMP binds to a conserved RNA structure called a riboswitch. Riboswitches traditionally function by controlling the expression of the downstream gene on the same RNA segment. In V. cholerae, this riboswitch is designated as Vc2. However, preliminary experiments suggest that binding of c-di-GMP to Vc2 actually increases the stability of an upstream small RNA (sRNA), which then appears to impact bacterial behaviors. This project will focus on how (a) binding of c-di-GMP to Vc2 stabilizes the traget sRNAs; (b)the Vc2 target genes are regulated; and (c) the Vc2 RNAs impacts the biology of the bacterium. This research is likely to uncover a novel genetic regulatory mechanism that governs the transitioning between distinct phases of biofilm formation. Moreover, discoveries from this project will inspire new approaches to cultivate beneficial biofilms while inhibiting harmful ones.Broader Impacts: This project will also serve as a platform to broadly engage members of the academic community and the general public in scientific education and discourse. During the period of this award, undergraduate and graduate students in an upper level microbiology course (Microbial Genetics) and in the investigator's laboratory will be taught and mentored to become highly trained members of the future scientific community. The investigator will also initiate a number of activities to further engage the general public such as the organization of an annual "Microbiology Day" at "Impression 5" science center located in Lansing, MI. The investigator will also develop and teach a continuing education program titled "Hot Topics in Sciences" as part of the Evening College curriculum at MSU. This class will provide adults from the local community with the scientific principles behind a number of controversial science topics prevalent in the public consciousness. The project team will also instruct local high-school science teachers about microbial biofilms in the MSU "Frontiers in Science" program. Finally, the research team will train underrepresented students recruited from the Summer Research Opportunities (SROP) program offered by Michigan State University.

智力优势：所有生物体面临的一个基本决定是，是在给定的环境中定居还是迁移到新的环境中。对于细菌来说，这个决定包括在运动状态和固着的生物膜形成存在之间的转变。生物膜被定义为包裹在保护性细胞外基质中的多细胞细菌群落。生物膜是自然界中细菌生长的主要形式，并允许细菌在捕食、有毒化学品和恶劣条件下存活。因此，生物膜在每种环境中都代表着重要的生态位，并影响着农业、生物能源和水净化等工业应用。在过去的十年中，很明显，细胞内信号分子环二GMP（c-di-GMP）在绝大多数细菌中起着控制运动性和生物膜形成之间的过渡的基本作用。然而，c-di-GMP调节这些行为的分子机制还不清楚。本研究项目将研究c-di-GMP发挥其功能的新机制。在霍乱弧菌中，c-di-GMP与一种称为核糖开关的保守RNA结构结合。核糖开关传统上通过控制相同RNA片段上下游基因的表达来发挥功能。在霍乱弧菌中，这种核糖开关被命名为Vc 2。然而，初步实验表明，c-di-GMP与Vc 2的结合实际上增加了上游小RNA（sRNA）的稳定性，这似乎会影响细菌的行为。该项目将重点关注（a）c-di-GMP与Vc 2的结合如何稳定目标sRNA;（B）Vc 2靶基因受到调控;以及（c）Vc 2 RNA影响细菌的生物学。这项研究可能揭示一种新的遗传调控机制，该机制控制生物膜形成不同阶段之间的过渡。此外，该项目的发现将激发新的方法来培养有益的生物膜，同时抑制有害的生物膜。更广泛的影响：该项目还将作为一个平台，广泛吸引学术界和公众参与科学教育和讨论。在此期间，本科生和研究生在上层微生物学课程（微生物遗传学）和研究人员的实验室将被教导和指导，成为未来科学界训练有素的成员。研究者还将发起一些活动，以进一步吸引公众参与，例如在位于密歇根州兰辛的“印象5”科学中心组织年度“微生物学日”。调查员还将开发和教授一个名为“科学热点”的继续教育计划，作为密歇根州立大学夜校课程的一部分。本课程将为当地社区的成年人提供公众意识中普遍存在的一些有争议的科学话题背后的科学原理。 该项目小组还将指导当地高中科学教师在密歇根州立大学的“科学前沿”计划有关微生物生物膜。最后，研究小组将培训从密歇根州立大学提供的夏季研究机会（SROP）计划招募的代表性不足的学生。