Characterization of assembly factors for type IV secretion systems

IV 型分泌系统组装因子的表征

• 批准号: 10435561
• 负责人: Michael G. Caparon
• 金额: $ 25.42万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-21 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10435561
• 关键词: ATP phosphohydrolase; Address; Adherence; Appearance; Area; Bacterial Infections; Cell Wall; Cells; Cellular Structures; Complex; Cytoplasm; Disease; Distant; Electrons; Essential Genes; Future; Genes; Growth; In Situ; Insertional Mutagenesis; Intervention; Knowledge; Legionella; Legionella pneumophila; Legionnaires' Disease; Mammalian Cell; Massive Parallel Sequencing; Mediating; Membrane; Membrane Proteins; Methods; Modeling; Multiprotein Complexes; Mutagenesis; Mutation; Organism; Pilum; Play; Pneumonia; Protein Disulfide Isomerase; Proteins; Research; Research Design; Role; Scientist; Structure; System; Testing; Therapeutic; Therapeutic Intervention; Toxin; Type IV Secretion System Pathway; Virulence; Work; base; cell motility; citrate carrier; cytochrome c; disulfide bond; insight; macrophage; membrane assembly; mutant; new therapeutic target; novel; pathogen; pathogenic bacteria; periplasm; transposon sequencing

Abstract Many bacterial pathogens employ complex, specialized secretion systems to export toxins and deliver effectors into the cytoplasm of mammalian cells. Although a significant amount of work has been done on identifying components of these secretion systems, less is known about the factors that are required for their assembly/function. We propose to identify and characterize these assembly factors by studying the type IVB secretion system of Legionella pneumophila. This system, called Dot/Icm, is used by L. pneumophila to survive and replicate within alveoloar macrophages, thereby mediating a pneumonia-like disease called Legionnaires’ disease. The L. pneumophila T4BSS is encoded by approximately thirty dot/icm genes. These genes are essential for intracellular replication and virulence of this pathogen, but most are not required for growth of the organism on media. However, dotL is an essential gene under all conditions and a large number of suppressors can be isolated that allow a ∆dotL strain to live. These suppressors include mutations in other dot/icm genes and in a number of putative assembly factors including DjlA and LdsA. Based on these observations, we propose to isolate additional ∆dotL lethality suppressors using Tn-seq and to elucidate how DjlA and LdsA function in the assembly/function of the Dot/Icm T4BSS. Information acquired will provide insight into how L. pneumophila’s T4BSS assembles and functions and may reveal novel targets for drug intervention.

抽象的 许多细菌病原体员工复合物，专门的分泌系统，用于导出毒素并提供 哺乳动物细胞细胞质的效应子。尽管已经完成了大量的工作 识别这些分泌系统的组成部分，对这些因素所需的因素知之甚少 他们的组装/功能。我们建议通过研究 型军团菌的IVB分泌系统。该系统称为DOT/ICM，由L。使用。 肺炎生存和复制在肺泡巨噬细胞中，从而介导类似肺炎 疾病称为军团病。肺炎L. t4bss编码约三十 点/ICM基因。这些基因对于这种病原体的细胞内复制和病毒至关重要，但是 大多数人在培养基上生长并不是必需的。但是，dotl是所有基因的基因 可以隔离条件和大量补充剂，以使∆DOTL应变生存。这些 补充剂包括其他点/ICM基因中的突变以及许多推定的装配因子 包括DJLA和LDSA。基于这些观察结果，我们建议隔离其他∆DOTL致死性 补充使用TN-Seq并阐明DJLA和LDSA在汇编/功能中的功能 点/ICM T4BS。获取的信息将提供有关肺炎L. t4bss如何组装的洞察力 和功能，并可能揭示了药物干预的新目标。