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Bifunctional Control of Yop Translocation by YopK

YopK 对 Yop 易位的双功能控制

基本信息

批准号：
9058462
负责人：
Melanie Marketon
金额：
$ 41.25万
依托单位：
TUFTS UNIVERSITY BOSTON
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-12-04 至 2018-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9058462
关键词：
Actins Address Alleles Antibiotic Resistance Architecture Attenuated Back Bacteria Binding Biochemical Biochemistry Bioinformatics Biological Models Bubonic Plague Cell membrane Cells Cellular biology Complex Coupled Cystic Fibrosis Data Disease Drug Design Drug Targeting Ensure Genetic Health Healthcare Systems Heart Homologous Gene Human Individual Infection Injection of therapeutic agent Location Mediating Methods Modeling Molecular Monitor Nature Needles Protein Secretion Proteins Recruitment Activity Regulation Role Side Structure Substrate Specificity Surface Syringes System Testing Toxin Type III Secretion System Pathway Virulence Virulence Factors Work Yersinia Yersinia pestis antimicrobial base cytotoxicity design feeding foodborne illness high throughput screening insight mimicry mutant novel pathogen polymerization prevent research study response therapeutic target tissue/cell culture tool weapons

项目摘要

DESCRIPTION (provided by applicant): Type III secretion is a method of delivering toxic proteins directly into host cells via a molecular syringe- like structure, which is employed by many Gram-negative pathogens. Type III secretion systems contribute to an incredibly diverse range of diseases in humans including bubonic plague, food-borne illnesses, and cystic fibrosis. The millions of cases each year of food-borne illnesses alone have a staggering impact on our health care system. Add to that the increasingly deadly potential from emerging antibiotic resistance, and the need for new antimicrobial treatments is urgent. Though the toxins that are delivered by individual pathogens vary, the fundamentals of assembling and deploying type III secretion systems are well conserved and represent a potential therapeutic target. To design effective strategies that disable this virulence factor, a better understanding of its architecture and regulation is necessary. Type III secretion systems are generally only made and activated during infection of a susceptible host. During infection, bacteria assemble the needle-like structure, but toxins are not secreted through it until contact with a host cell is made. How do bacteria activate the secretion system upon cell contact? Just as important, how do they shut if off? These questions are fundamental to our understanding of the system, and these questions are the focus of this proposal. We study the Yersinia type III secretion system because it is a well-established model system. Our novel tools and approaches have revealed new insight into the heart of type III secretion regulation. In particular, we have found that YopK, a regulator of type III secretion, has two distinct regulatory functions and works at both ends of the "needle". I appears that YopK is an integral component of an ON/OFF switch for secretion. From the bacterial side, YopK helps to monitor which proteins are secreted through the needle. YopK itself is secreted and once inside the host cell, YopK interacts with the end of the needle complex to shut down secretion of the toxins. In this proposal we will investigate how YopK performs these activities. Using a combination of genetics, cell biology, and biochemistry we will determine how YopK coordinates with other known secretion regulators on both sides of the needle. We will also identify and characterize the functional domains within YopK that mediate its activities. Collectively, our work will reveal fundamental mechanisms controlling this important virulence weapon. If we understand the nature of the ON/OFF switch, we can design a new type of broad-spectrum drug that targets a vital secretion system in a wide range of bacteria.

描述（由申请人提供）：III型分泌是一种通过分子注射器样结构将有毒蛋白质直接递送到宿主细胞中的方法，许多革兰氏阴性病原体都采用这种方法。 III 型分泌系统导致人类多种疾病，包括黑死病、食源性疾病和囊性纤维化。每年数以百万计的食源性疾病病例就对我们的医疗保健系统产生了惊人的影响。再加上新出现的抗生素耐药性带来的日益致命的可能性，迫切需要新的抗菌治疗方法。尽管各个病原体释放的毒素各不相同，但组装和部署 III 型分泌系统的基本原理得到了很好的保存，并代表了潜在的治疗靶点。为了设计禁用这种毒力因子的有效策略，更好地了解其架构并且监管是必要的。 III型分泌系统通常仅在易感宿主感染期间产生和激活。在感染过程中，细菌会组装出针状结构，但在与宿主细胞接触之前，毒素不会通过它分泌。细菌如何在细胞接触时激活分泌系统？同样重要的是，如果关闭，它们如何关闭？这些问题是我们理解系统的基础，也是本提案的重点。我们研究耶尔森氏菌 III 型分泌系统，因为它是一个完善的模型系统。我们的新颖工具和方法揭示了对 III 型分泌调节核心的新见解。特别是我们发现，III型分泌调节因子YopK具有两种截然不同的调节功能，作用于“针”的两端。我认为 YopK 是分泌开关的一个组成部分。从细菌方面来说，YopK 有助于监测通过针头分泌的蛋白质。 YopK 本身是分泌的，一旦进入宿主细胞，YopK 就会与针复合物的末端相互作用，从而停止毒素的分泌。在本提案中，我们将研究 YopK 如何执行这些活动。结合遗传学、细胞生物学和生物化学，我们将确定 YopK 如何与针两侧其他已知的分泌调节剂协调。我们还将识别并描述 YopK 内调节其活动的功能域。总的来说，我们的工作将揭示控制这种重要毒力武器的基本机制。如果我们了解开/关开关的本质，我们就可以设计一种新型广谱药物，针对多种细菌的重要分泌系统。