Characterization of the mechanisms underpinning quorum sensing progression in Pseudomonas aeruginosa

铜绿假单胞菌群体感应进展机制的表征

• 批准号: 10726940
• 负责人: Jon E Paczkowski
• 金额: $ 5.61万
• 依托单位: WADSWORTH CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10726940
• 关键词: Affect; Affinity; Anti-Bacterial Agents; Architecture; Bacteria; Behavior; Binding; Biochemical; Biological Assay; Carrier Proteins; Cell Communication; Cell Cycle; Cell Density; Cell Signaling Process; Cells; ChIP-seq; Clinical; Communication; Communities; Complex; DNA; DNA Binding; DNA Binding Domain; Data; Deoxyribonucleases; Detection; Development; Down-Regulation; Environment; Enzymes; Gene Expression; Gene Expression Profile; Genes; Genetic Transcription; Goals; Growth; High-Throughput Nucleotide Sequencing; In Vitro; Infection; Ligands; Light; Maps; Mediating; Medicine; Microbial Biofilms; Molecular; Molecular Conformation; Mutagenesis; Mutation; Organism; Output; Pathogenesis; Phase; Play; Process; Production; Proteins; Pseudomonas aeruginosa; Pseudomonas aeruginosa infection; Regulation; Regulatory Element; Regulon; Relaxation; Reporter; Repression; Role; Shapes; Signal Transduction; Signal Transduction Pathway; Signaling Molecule; Specificity; Structure; System; Techniques; Therapeutic; Time; Transcriptional Regulation; Up-Regulation; Virulence; Virulence Factors; X-Ray Crystallography; combat; cost; experimental study; extracellular; genetic approach; human pathogen; in vivo; insight; metalloenzyme; microbial community; novel; pathogenic bacteria; prevent; promoter; protein folding; protein protein interaction; quorum sensing; receptor; receptor binding; response; rhamnolipid; surfactant; trait; transcription factor; transcriptome sequencing; transmission process

PROJECT SUMMARY Quorum sensing (QS) is a mechanism of cell-cell communication that bacteria use to orchestrate collective behaviors, including virulence and biofilm formation. QS relies on the production, release, and group- wide detection of extracellular signal molecules called autoinducers (AI). QS allows bacteria to synchronously alter gene expression patterns that underpin collective behaviors, for example, biofilm formation. Some receptors bind and respond exclusively to one AI, while others bind and respond to multiple AIs. QS is responsible for releasing public goods that are beneficial to kin and, potentially, non-kin, and as a result, it plays an important role in shaping microbial community architecture. QS is now understood to be the norm in the bacterial world. Nonetheless, how different bacterial QS receptors initiate signal transduction is not understood. Defining the mechanisms that regulate QS-mediated production of public goods will be key for generally understanding how organisms coordinate community level changes in gene expression. This is particularly important in light of our findings that P. aeruginosa QS can be activated by signals produced by non-kin. Thus, determining the mechanisms that regulate QS progression after signal recognition will allow us to understand the respective benefits and drawbacks of strict versus relaxed ligand detection in QS-mediated communication. Bacteria live in heterogeneous communities and encounter mixtures of AIs produced by themselves, their kin, and their non-kin neighbors. Upon signal recognition, LasR and RhlR activate hundreds of genes, many of which are involved in pathogenesis and biofilm formation. While some signal transduction pathways follow a linear circuit, the QS system in P. aeruginosa is best described as a dense network of receptors and regulators with interconnecting regulatory systems and outputs. Canonically, the LasR-AI complex activates expression of rhlR and rhlI, thus launching the second QS system, enabling the two QS systems to function in tandem. Surprisingly, rhlR can be upregulated in clinical isolates containing lasR inactivating mutations. RhlR can also function without its partner synthase to regulate certain genes. This is achieved via a metallo-hydrolase known as PqsE. We discovered that PqsE and RhlR interact to form a complex. We will explore the role of PqsE in regulating RhlR function and describe their tandem role in transcriptional regulation and pathogenesis in AIM 1. The progression into QS corresponds to a downregulation of certain regulatory elements that function at low cell density to potentially mitigate early entry into QS. We have discovered that Fis, which is expressed during log phase, regulates the production of rhlA, a gene responsible for the synthesis of rhamnolipids, which are a bacterial surfactant important for infections. We will explore the mechanism Fis uses to achieve this regulation, in addition to what role it might play in regulating other QS genes and behaviors in AIM 2.

项目总结 群体感应(QS)是细菌用来协调细胞间通信的一种机制 集体行为，包括毒力和生物膜的形成。QS依赖于生产、发布和团队- 广泛检测称为自身诱导物(AI)的细胞外信号分子。QS允许细菌同步 改变支撑集体行为的基因表达模式，例如生物膜的形成。一些受体 绑定并仅响应一个AI，而其他绑定并响应多个AI。QS负责 释放对亲属和潜在的非亲属有益的公共产品，因此，它发挥着重要的作用 在塑造微生物群落结构方面的作用。QS现在被认为是细菌界的标准。 然而，不同的细菌QS受体如何启动信号转导尚不清楚。定义 监管QS介导的公共产品生产的机制将是普遍理解如何 生物体在基因表达上协调群落水平的变化。这尤其重要，因为我们的 发现铜绿假单胞菌QS可以被非亲缘关系产生的信号激活。因此，确定 信号识别后调节QS进程的机制将使我们能够理解各自的 QS介导的沟通中严格和松弛配基检测的优缺点。细菌生活在 异质社区和遇到由他们自己、他们的亲属和他们的非亲属制造的人工智能的混合 邻里。在信号识别后，LasR和RhlR激活了数百个基因，其中许多基因参与了 发病机制和生物膜的形成。虽然一些信号转导通路遵循线性电路，但QS 铜绿假单胞菌中的系统最好的描述是一个由受体和调节器组成的密集网络，它们相互连接 监管系统和产出。典型地，LasR-AI复合体激活了rh lR和rh lI的表达，从而 启动第二个QS系统，使两个QS系统能够同时运行。令人惊讶的是，rHLR可以 在含有LasR失活突变的临床分离株中上调。RhlR也可以在没有伙伴的情况下发挥作用 合酶来调节某些基因。这是通过一种被称为PqsE的金属水解酶实现的。我们发现 PqsE和RhlR相互作用形成复合体。我们将探讨PqsE在调节RhlR功能和 描述它们在转录调控和AIM发病机制中的串联作用1.向QS的进展 对应于某些调控元件的下调，这些元件在低细胞密度下发挥作用，可能 缓解早期进入QS的问题。我们已经发现，在对数阶段表达的FIS调节 生产rhlA，这是一种负责合成鼠李糖脂的基因，鼠李糖脂是一种细菌表面活性物质 对感染很重要。我们将探索FIS用来实现这一监管的机制，除了 它可能在调节AIM-2中的其他QS基因和行为中发挥作用。