QUORUM SENSING IN PSEUDOMONAS AERUGINOSA

铜绿假单胞菌中的群体感应

• 批准号: 2807379
• 负责人: Everett P Greenberg
• 金额: $ 23.76万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2003-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2807379
• 关键词: Escherichia coli; Pseudomonas aeruginosa; bacterial genetics; biofilm; biological signal transduction; gene expression; genetic manipulation; genetic mapping; genetic promoter element; genetic regulation; microorganism culture; microorganism growth; microorganism population study; transcription factor; Escherichia coli; Pseudomonas aeruginosa; bacterial genetics; biofilm; biological signal transduction; gene expression; genetic manipulation; genetic mapping; genetic promoter element; genetic regulation; microorganism culture; microorganism growth; microorganism population study; transcription factor

Quorum sensing, the ability of a bacterial species to monitor its own population density and activate specific genes at appropriate densities, is a common trait, critical for adaptation to environmental changes. These are two quorum sensing systems in Pseudomonas aeruginosa that control an ill-defined battery of virulence genes. One of the systems also is required for development of P. aeruginosa biofilms. The aims of the proposed research are to identify the genes controlled by each of the two systems and to determine whether control of individual genes is direct of indirect. We will also determine which of the target genes we identify are required for biofilm development. Two approaches will be taken to identify target genes. I.P. aeruginosa quorum sensing mutants will be employed to identify proteins expressed at higher levels with or without each of the signal molecules. II. Mutagenesis of a P. aeruginosa quorum sensing null mutant with promoter probe transposons will be used to identify genes that require for their expression, the presence or absence of either of the quorum sensing signals. To determine whether quorum sensing control of target genes is direct of indirect we will examine expression of lacZ fusions to target gene promoters in recombinant Escherichia coli. To determine which targets of quorum sensing are required for normal biofilm development we will test mutants identified as quorum sensing regulated for their ability to form typical P. aeruginosa structured, biocide resistant biofilms. It is clear that the role of quorum sensing in the general regulatory circuits of the cell is complex, yet this has not been investigated systematically. The proposed research will open a new area of study in bacterial cell-to-cell communication. P. aeruginosa is an appropriate model for these studies for several reasons. The genome is being sequenced (most of the genome sequence is already available for analysis). There are two well-characterized quorum sensing systems in P. aeurginosa and appropriate null mutations have been constructed. Although there have been no systematic surveys, we know that quorum sensing in P. aeruginosa controls expression of many unlinked genes. Quorum sensing has been shown to be critical for P. aeruginosa virulence in several animal or plant model systems.

群体传感是细菌物种监测其自身种群密度并以适当密度激活特定基因的能力，是一种常见的特征，对于适应环境变化至关重要。 这是铜绿假单胞菌中的两个法定感应系统，可控制不确定的毒力基因。 开发铜绿假单胞菌生物膜也需要其中之一。 拟议研究的目的是确定由两个系统中每个系统控制的基因，并确定单个基因的控制是否是间接的直接。 我们还将确定生物膜开发所必需的靶基因。 将采用两种方法来识别靶基因。 I.P.将使用铜绿群体传感突变体来鉴定在有或没有每个信号分子的情况下以较高水平表达的蛋白质。 ii。使用启动子探针转座子的铜绿假单胞菌群体传感零突变体的诱变将用于识别需要其表达的基因，存在或不存在任何一个Quorum传感信号。 为了确定靶基因的群体传感控制是否是间接的直接，我们将检查LACZ融合在重组大肠杆菌中对靶基因启动子的表达。 为了确定正常生物膜发育需要哪些群体传感靶标，我们将测试被确定为法规传感的突变体，该突变体对其形成典型的铜绿假单胞菌结构，耐生物剂的耐生物膜。 显然，法定感应在细胞的一般调节回路中的作用很复杂，但尚未系统地研究。 拟议的研究将在细菌细胞到细胞通信方面开设一个新的研究领域。 铜绿假单胞菌是这些研究的合适模型，原因有几个。 正在测序基因组（大多数基因组序列已经可用于分析）。 假单胞菌中有两个特征良好的群体传感系统，并构建了适当的无效突变。 尽管没有系统的调查，但我们知道，铜绿假单胞菌中的法定人数控制着许多未链接基因的表达。 在几种动物或植物模型系统中，群体传感对铜绿假单胞菌的毒力至关重要。