Roles for five small RNAs required for quorum sensing in Vibrio harveyi

哈维氏弧菌群体感应所需的 5 个小 RNA 的作用

基本信息

批准号：
8069930
负责人：
Steven Thomas Rutherford
金额：
$ 5.13万
依托单位：
PRINCETON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-04-01 至 2013-03-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): My overarching goal is to understand the molecular mechanisms underpinning collective behaviors. To explore this, I will study quorum sensing, the process of cell-cell communication in the model bacterium Vibrio harveyi: Using quorum sensing, bacteria produce, detect, and respond to extracellular signal molecules (autoinducers) to coordinate gene expression on a population-wide scale. In V. harveyi, five regulatory small RNAs (called Qrr sRNAs) are produced at low cell densities and act to destabilize the luxR mRNA encoding the master quorum-sensing regulator, LuxR. My goal is to understand what features having five Qrr sRNAs rather than one sRNA provides the V. harveyi quorum-sensing circuit, and, more generally, what features sRNAs rather than regulatory proteins provide to signaling networks. Specifically, I will address the following points. 1) Define the transcription factors that individually control each qrr sRNA gene. The five c/rr sRNA gene promoters are divergent, and each gfrrsRNA gene shows a distinct pattern of gene expression, suggesting that different transcription factors regulate expression of each Qrr sRNA gene. I propose to identify these transcription factors and characterize their roles in the V. harveyi quorum-sensing response. 2) Identify mRNA targets that are exclusive to each Qrr sRNA. I will identify genes regulated exclusively by each of the V. harveyi Qrr sRNAs and determine the quorum-sensing functions of the identified targets. 3) Determine how different Qrr sRNA affinities for target mRNAs establish an ordered program of quorum-sensing gene expression. I propose that the Qrr sRNAs bind with different affinities to mRNA targets and this affects the timing of the various quorum-sensing response outputs. I will compare binding strengths of the Qrr sRNAs with known V. harveyi mRNA targets, define the sequence requirements for Qrr sRNA binding, and how altering those binding properties affects the timing of quorum- sensing gene expression. An important practical aspect of our quorum-sensing investigations is that they are leading to the development of anti-quorum-sensing therapies for use as alternatives to traditional antibiotics. Similarly, a molecular understanding of quorum sensing in beneficial bacteria, such as those that produce medical, agricultural, or industrial products of importance, could facilitate the development and implementation of pro- quorum-sensing strategies that improve industrial-scale production of commercially relevant natural products.

描述（由申请人提供）：我的首要目标是了解支撑集体行为的分子机制。为了探索这一点，我将研究群体感应，即模型细菌哈维氏弧菌中细胞间通讯的过程：利用群体感应，细菌产生、检测和响应细胞外信号分子（自诱导剂），以协调群体的基因表达——规模大。在 V. harveyi 中，五种调节性小 RNA（称为 Qrr sRNA）在低细胞密度下产生，并破坏编码主群体感应调节因子 LuxR 的 luxR mRNA 的稳定性。我的目标是了解具有 5 个 Qrr sRNA 而不是 1 个 sRNA 的特征为 V. harveyi 群体感应电路提供了哪些特征，更一般地说，是 sRNA 而不是调节蛋白为信号网络提供了哪些特征。具体来说，我会讲以下几点。 1) 定义单独控制每个 qrr sRNA 基因的转录因子。五个 c/rr sRNA 基因启动子是不同的，每个 gfrrsRNA 基因显示出不同的基因表达模式，表明不同的转录因子调节每个 Qrr sRNA 基因的表达。我建议鉴定这些转录因子并描述它们在 V. harveyi 群体感应反应中的作用。 2) 识别每个 Qrr sRNA 独有的 mRNA 靶标。我将鉴定由每个 V. harveyi Qrr sRNA 专门调控的基因，并确定已识别靶标的群体感应功能。 3) 确定不同的 Qrr sRNA 对目标 mRNA 的亲和力如何建立群体感应基因表达的有序程序。我认为 Qrr sRNA 以不同的亲和力与 mRNA 靶标结合，这会影响各种群体感应响应输出的时间。我将比较 Qrr sRNA 与已知的哈维氏弧菌 mRNA 靶标的结合强度，定义 Qrr sRNA 结合的序列要求，以及改变这些结合特性如何影响群体感应基因表达的时间。我们的群体感应研究的一个重要的实际方面是，它们正在导致抗群体感应疗法的开发，以用作传统抗生素的替代品。同样，对有益细菌（例如生产重要的医疗、农业或工业产品的细菌）群体感应的分子理解可以促进原群体感应策略的开发和实施，从而改善商业相关天然物质的工业规模生产。产品。