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: 10288771
• 负责人: Joseph P Vogel
• 金额: $ 21.28万
• 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 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10288771
• 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 许多细菌病原体采用复杂、专门的分泌系统来输出毒素并传递 尽管已经进行了大量工作，但仍将效应子引入到哺乳动物细胞的细胞质中。 识别这些分泌系统的组成部分，对于其所需的因素知之甚少 我们建议通过研究来识别和表征这些组装因素。 嗜肺军团菌 IVB 型分泌系统 该系统称为 Dot/Icm，由嗜肺军团菌使用。 嗜肺军团菌在肺泡巨噬细胞内生存和复制，从而介导肺炎样 嗜肺军团菌 T4BSS 由大约 30 个编码。 dot/icm 基因对于这种病原体的细胞内复制和毒力至关重要，但是 大多数基因都不是有机体在培养基上生长所必需的，但是 dotL 是所有基因中的必需基因。 可以分离出允许 ΔdotL 菌株存活的条件和大量抑制子。 抑制因子包括其他 dot/icm 基因和许多假定的组装因子中的突变 包括 DjlA 和 LdsA 根据这些观察结果，我们建议分离额外的 ΔdotL 致死率。 使用 Tn-seq 抑制器并阐明 DjlA 和 LdsA 在 Dot/Icm T4BSS。获得的信息将有助于深入了解嗜肺军团菌的 T4BSS 的组装方式。 和功能，并可能揭示药物干预的新靶标。