Dissecting the means by which type 3 substrates are defined & secreted

剖析 3 类底物的定义方式

• 批准号: 10553659
• 负责人: CAMMIE LESSER
• 金额: $ 50.09万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10553659
• 关键词: ATP phosphohydrolase; Address; Binding; Biochemical; Biological Assay; Biological Models; Cells; Complex; Cytosol; Data; Development; Disease; Dissociation; Engineering; Escherichia; Escherichia coli; Family; Genetic; Goals; Human; Infection; Lead; Mammalian Cell; Mediating; Membrane; Modeling; Molecular; Molecular Chaperones; Multi-Drug Resistance; Mutagenesis; N-terminal; Nature; Pathogenicity; Pathway interactions; Pharmaceutical Preparations; Phylogenetic Analysis; Physiological; Play; Process; Protein Secretion; Proteins; Proton-Motive Force; Pseudomonas aeruginosa; Publishing; RNA; Ribosomes; Role; Salmonella; Salmonella enterica; Shigella; Shigella flexneri; Solid; Sorting; Technology; Translations; Type III Secretion System Pathway; Variant; Virulence; Yersinia; antimicrobial; antimicrobial drug; experimental study; follow-up; genetic approach; high throughput screening; in vivo; insight; nanomachine; novel; pathogen; pathogenic bacteria; recruit; resistant strain; ribosome profiling; targeted agent

The virulence of many human bacterial pathogens is dependent on transkingdom nanomachines, including type III secretion systems (T3SSs), which act to directly deliver tens of virulence proteins, often referred to as effectors, into the cytosol of mammalian cells. Many critical gaps exist in our understanding of how type III secreted (T3S) proteins, referred to as effectors, are defined and delivered to the T3S apparatus (T3SA). While each pathogen injects its own unique set of effectors into hosts, components of their machines share a high degree of similarity. For several decades, the dogma has been that the effector secretion is dependent on small acidic T3S chaperones that bind to their N-terminal regions. These chaperones control the hierarchy of secretion of proteins by mediating their recruitment to the sorting platform, a complex that cycles between the cytosol and membrane-embedded T3SA. Interestingly, cognate chaperones have not yet been identified for the majority of T3S effectors, including those from intensively studied Salmonella, Yersinia, Shigella and pathogenic Escherichia T3SSs. Here, we present data that support the existence of a noncanonical T3SS chaperone-independent (CI) pathway likely conserved across numerous phylogenetically distinct T3SS families. Here, using the Shigella flexneri T3SS as a model system, we propose to: 1. Determine how T3S chaperones are recruited to the sorting platform. Using the Protein Interaction 2. Dissect the molecular mechanisms by which CI effectors are recognized and delivered to the T3SA. 3. Investigate the existence of a co-translational ATPase-independent type III secretion pathway. Together the proposed studies shown not only advance our understanding regarding how T3S effectors are defined and delivered to the T3SA, but also result in the identification of targets for the development of novel antimicrobial agents that target the virulence of the large family of Gram-negative bacterial pathogens whose virulence is dependent on a functional T3SS.

许多人类细菌病原体的毒力取决于跨性纳米机器，包括 III型分泌系统（T3SSS），其直接传递数十种毒力蛋白，通常称为 效应子，进入哺乳动物细胞的细胞质。我们对III类型的理解中存在许多关键差距 分泌的（T3S）蛋白（称为效应子）被定义并传递到T3S设备（T3SA）。尽管 每种病原体都将自己独特的效应子注入宿主，其机器的组件共享高度 相似程度。几十年来，教条一直是效应子分泌取决于 与N末端区域结合的小酸性T3S伴侣。这些伴侣控制 通过将蛋白质的分泌通过将其招募介导为排序平台，这一复杂的循环 细胞质和膜包裹的T3SA。有趣的是，尚未确定同源伴侣 大多数T3效应子，包括来自深入研究的沙门氏菌，耶尔森氏菌，志贺氏菌和 致病性大肠t3ss。在这里，我们提供支持存在非规范T3SS的数据 伴侣独立的（CI）途径可能在许多系统发育上的T3S中保守 家庭。在这里，使用Shigella Flexneri T3SS作为模型系统，我们建议： 1。确定如何将T3S伴侣招募到分类平台。使用蛋白质相互作用 2。解剖CI效应子被识别并传递到T3SA的分子机制。 3。研究共同翻译ATPase独立于III型分泌途径的存在。 拟议的研究共同表明，不仅提高了我们对T3效应子的理解 定义并交付给T3SA，但也导致鉴定出新的目标 靶向大型革兰氏阴性细菌病原体的毒力的抗菌剂 毒力取决于功能性T3SS。