Chemical biology of type IV secretion systems

IV型分泌系统的化学生物学

基本信息

批准号：
10569670
负责人：
Carrie Shaffer
金额：
$ 26.79万
依托单位：
UNIVERSITY OF KENTUCKY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-03-01 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10569670
关键词：
2-hydroxypyridine Acceleration Address Antibiotic Resistance Bacteria Bacterial Genome Basic Science Biochemical Biogenesis Biological Biological Assay Biology C10 Cells Cellular biology Centers of Research Excellence Chemicals Clinical Collaborations Complement Complex DNA Destinations Development Discipline Engineering Epithelial Cells Escherichia coli Eukaryotic Cell Exhibits Faculty Fostering Foundations Genetic Goals Helicobacter pylori Impairment Infection Infectious Diseases Research Knowledge Lead Libraries Ligand Binding Lipids Lipopolysaccharide Biosynthesis Pathway Mechanics Mediating Medical Microscopy Molecular Molecular Machines Molecular Probes Nucleic Acids Nucleoproteins Oncoproteins Organic Synthesis Outcome Pathogenesis Pathogenicity Island Peptidoglycan Pharmaceutical Chemistry Pharmacologic Substance Phenotype Pilum Plant Model Play Polysaccharides Prokaryotic Cells Proteins Regulation Research Research Design Resolution Resources Rhizobium radiobacter Risk Role Series Signal Pathway Stomach Stomach Diseases Structure-Activity Relationship System Systems Biology Therapeutic Toxin Type IV Secretion System Pathway Validation Virulence Work antimicrobial appendage carcinogenicity cell envelope design extracellular genetic approach high throughput screening inhibitor innovation insight interdisciplinary approach malignant stomach neoplasm microbial microbiome model development mutant nanomachine novel pathogen pathogenic bacteria pharmacophore protein complex rational design repository response scaffold scale up screening small molecule system architecture tool tumorigenic virtual screening

项目摘要

PROJECT SUMMARY Bacteria have evolved specialized nanomachines to deliver microbial cargo across the cell envelope. One versatile translocation apparatus, the type IV secretion system (T4SS), can be strategically deployed to inject macromolecular substrates into target bacterial or eukaryotic recipient cells. Despite their importance in bacterial pathogenesis and dissemination of antibiotic resistance determinants, the mechanisms by which the T4SS assembles and transports payload remain largely undefined. To address this knowledge gap, the long-term goal of this proposal is to develop and apply robust molecular tools to accelerate fundamental studies of T4SS nanomachines. The cag T4SS of the gastric bacterium Helicobacter pylori has emerged as an important system for understanding how a single molecular machine can transport diverse cargo into target cells. Whereas some T4SS have the capacity to secrete hundreds of proteins or DNA-protein complexes into the host cell, the ability to translocate a diverse repertoire of lipid, nucleic acid, protein, and polysaccharide substrates distinguishes the cag T4SS from other systems. Notably, the bacterial oncoprotein CagA is rapidly delivered to host gastric cells via cag T4SS mechanisms. Translocated H. pylori effector molecules activate innate defenses and dysregulate signaling pathways that influence progression of gastric disease; consequently, colonization by cag T4SS- positive H. pylori significantly augments the risk for gastric cancer. As a result of its central role in bacterial pathogenesis, the T4SS represents an ideal target for antimicrobials. In this application, we propose to identify and mechanistically characterize novel small molecule-based T4SS modulators. Iterative structure-activity relationship studies will be used to develop chemical scaffolds and pharmacophores with optimized anti-virulence potential. Probe development will take advantage of expertise and assay platforms in the Shaffer lab and will leverage synergistic resources in the proposed CPRI Computational Core (ligand-binding model development, rational design, virtual screening), CPRI Translational Core (high throughput assay support, novel compound repositories, and ADMET profiling), and the Organic Synthesis Core (medicinal chemistry and scale-up). Prioritized and validated chemical probes will be used in conjunction with biochemical and genetic approaches to interrogate cag T4SS regulation and dynamic steps in substrate translocation. Using a similar multidisciplinary approach, we will determine how the H. pylori cag T4SS apparatus assembles at the bacteria-host cell interface. Collectively, these studies will stimulate new basic research directions and will provide important insight into how the T4SS nanomachine orchestrates the delivery of specific molecular cargo to target cells to drive microbial pathogenesis. Furthermore, this work will generate powerful chemical tools that are broadly applicable to infectious disease research, and will identify potent lead compounds with the potential to disarm T4SS function in a variety of medically-relevant pathogens.

项目概要细菌已经进化出了专门的纳米机器，可以在细胞膜上运送微生物货物。一多功能易位装置，IV 型分泌系统（T4SS），可以战略性地部署来注射大分子底物进入目标细菌或真核受体细胞。尽管它们在细菌中很重要抗生素耐药性决定因素的发病机制和传播，T4SS 的机制组装和运输有效载荷在很大程度上仍然没有定义。为了解决这一知识差距，长期目标该提案的目的是开发和应用强大的分子工具来加速 T4SS 的基础研究纳米机器。胃细菌幽门螺杆菌的 cag T4SS 已成为一个重要的系统了解单个分子机器如何将不同的货物运输到目标细胞中。而有些 T4SS 能够将数百种蛋白质或 DNA-蛋白质复合物分泌到宿主细胞中，易位多种脂质、核酸、蛋白质和多糖底物的特点是来自其他系统的 cag T4SS。值得注意的是，细菌癌蛋白 CagA 被快速递送至宿主胃细胞通过 cag T4SS 机制。易位的幽门螺杆菌效应分子激活先天防御并失调影响胃病进展的信号通路；因此，cag T4SS-的定植幽门螺杆菌阳性会显着增加患胃癌的风险。由于其在细菌中的核心作用从发病机制来看，T4SS 代表了抗菌药物的理想靶点。在此应用中，我们建议确定并对基于小分子的新型 T4SS 调制器进行机械表征。迭代结构-活动关系研究将用于开发具有优化抗毒力的化学支架和药效团潜在的。探针开发将利用 Shaffer 实验室的专业知识和检测平台，并将利用拟议的 CPRI 计算核心中的协同资源（配体结合模型开发、合理设计、虚拟筛选）、CPRI Translational Core（高通量分析支持、新型化合物存储库和 ADMET 分析），以及有机合成核心（药物化学和放大）。经过优先考虑和验证的化学探针将与生化和遗传方法结合使用探究 cag T4SS 调节和底物易位的动态步骤。使用类似的多学科通过这种方法，我们将确定幽门螺杆菌 cag T4SS 装置如何在细菌-宿主细胞界面处组装。总的来说，这些研究将激发新的基础研究方向，并将提供重要的见解 T4SS 纳米机器协调将特定分子货物输送到目标细胞以驱动微生物发病。此外，这项工作将产生强大的化学工具，广泛适用于传染病研究，并将鉴定具有解除 T4SS 功能潜力的有效先导化合物存在于多种医学相关的病原体中。