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.

项目摘要 法群传感（QS）是细菌用于编排的细胞 - 细胞通信的机制 集体行为，包括毒力和生物膜形成。 QS依靠生产，发行和群体 - 广泛检测称为自动诱导剂（AI）的细胞外信号分子。 QS允许细菌同步 改变基因表达模式，即基于集体行为，例如生物膜形成。一些受体 绑定和响应一个AI，而其他AI则绑定并响应多个AI。 QS负责 释放有利于亲戚及其非亲属的公共物品，结果，它起着重要的作用 在塑造微生物社区体系结构中的作用。 QS现在被认为是细菌世界中的常态。 但是，不同的细菌QS受体如何启动信号转导。定义 调节QS介导的公共物品生产的机制将是一般了解如何理解的关键 生物体协调基因表达的变化。鉴于我们的看法，这一点尤其重要 铜绿假单胞菌QS的发现可以通过非金属产生的信号激活。因此，确定 在信号识别后调节QS进展的机制将使我们能够理解各自的 QS介导的沟通中严格与放松配体检测的好处和缺点。细菌居住 自己，亲属和非亲属产生的AIS的异质社区和遇到的混合物 邻居。通过信号识别，LASR和RHR激活了数百个基因，其中许多基因参与 发病机理和生物膜形成。虽然某些信号转导途径遵循线性电路，但QS 铜绿假单胞菌中的系统最好被描述为与互连的受体和调节剂的密集网络 监管系统和输出。在规范上，LASR-AI复合物激活了RHLR和RHLI的表达，因此 启动第二个QS系统，使两个QS系统可以同时起作用。出人意料的是，RHL可能是 在含有LASR灭活突变的临床分离株中上调。 RHLR也可以在没有伴侣的情况下运行 合成酶调节某些基因。这是通过称为PQSE的金属溶质酶实现的。我们发现了 PQSE和RHLR相互作用以形成复合物。我们将探讨PQSE在调节RHLR功能和 描述它们在AIM 1中的转录调控和发病机理中的串联作用。 对应于某些调节元件的下调，这些调节元件在低细胞密度下起作用 减轻早期进入QS。我们发现在日志阶段表达的FIS调节了 RHLA的产生，RHLA是负责合成鼠李糖脂的基因，后者是细菌表面活性剂 对于感染很重要。我们将探索FIS用于实现此法规的机制 它可能在AIM 2中调节其他QS基因和行为方面发挥作用。