A molecular switch of the type III secretion system in Chlamydia trachomatis

沙眼衣原体III型分泌系统的分子开关

基本信息

批准号：
8509139
负责人：
LI SHEN
金额：
$ 35.54万
依托单位：
LSU HEALTH SCIENCES CENTER
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-08-01 至 2015-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8509139
关键词：
Affect Bacteria Binding Biological Assay Cell membrane Cell-Free System Cells Chlamydia Chlamydia Infections Chlamydia trachomatis Complex Coupled Cytosol DNA-Directed RNA Polymerase Data Disease Drug Delivery Systems Ectopic Pregnancy Escherichia coli Event Gene Expression Genes Genetic Genetic Transcription Genital system Gram-Negative Bacteria Hela Cells Immunity In Vitro Infection Infertility Knowledge Mediating Membrane Modeling Molecular Molecular Chaperones Mutagenesis Needles Operon Pathogenesis Pelvic Inflammatory Disease Polymerase Process Property Proteins Public Health Regulation Regulon Research Role Sexually Transmitted Diseases Signal Transduction System Testing Transcriptional Regulation Type III Secretion System Pathway Virulence Woman Work base enteropathogenic Escherichia coli genetic manipulation insight member mutant novel pathogen promoter protein complex protein protein interaction reconstitution tool

项目摘要

DESCRIPTION (provided by applicant): A molecular switch of the type III secretion system in Chlamydia trachomatis The obligate intracellular bacterium C. trachomatis is the causative agent of the most common sexually transmitted disease worldwide and represents a significant public health burden. The severe sequelae of genital chlamydial infections in women include pelvic inflammatory disease, ectopic pregnancy and tubal infertility. A key virulence mechanism of C. trachomatis is the type III secretion system (T3SS) that directly delivers protein effectors into the host cell cytosol to subvert host immunity and enables bacterial survival in hosts. The objective of this project is to study the mechanism by which C. trachomatis controls type III secretion and gene expression, contributing to disease pathogenesis. We hypothesize that T3SS activity is regulated and coupled to gene transcription during C. trachomatis infection by a molecular switch, consisting of CT663 and its protein partners. This hypothesis is strongly supported by our novel finding that chlamydial CT663 is a bi-functional protein acting as both a transcription regulator that interacts with RNA polymerase containing ? 66 and a T3SS chaperone for CopN, which is a regulator as well as an effector of the T3SS. Our specific aims are: Aim 1. To test the hypothesis that CT663 forms a protein complex necessary for type III secretion activity. We will characterize the dynamic interactions of CT663 and its partners, and how these interactions impact the secretion activity using quantitative assays for protein-protein interactions, immunodetection, and an enteropathogenic Escherichia coli (EPEC) system. Aim 2. To test the hypothesis that CT663 differentially regulates the gene transcription. This aim will be achieved using our established transcription assays with reconstituted ?66RNA polymerase in vitro and in E. coli. These studies will uncover how T3SS activity affects gene expression during C. trachomatis infection and vice versa. This project will provide important insights into how C. trachomatis utilizes T3SS to survive in an intracellular niche by coordinating the regulatory events of the T3SS and gene expression during infection. Our research will significantly expand current knowledge of the C. trachomatis infection process and contribute to the identification of potential drug targets for new therapies that could significantly reduce the public health burden caused by C. trachomatis infection.

描述（由申请人提供）：沙眼衣原体中III型分泌系统的分子转换。专性细胞内细菌C. c. artarachomatis是全球最常见的性传播疾病的病因，代表着重大的公共卫生负担。女性生殖器衣原体感染的严重后遗症包括盆腔炎症性疾病，异位妊娠和输卵管不育症。沙眼梭状芽胞庭的关键毒力机制是III型分泌系统（T3SS），该系统将蛋白质效应子直接传递到宿主细胞胞质溶胶中，以颠覆宿主的免疫，并在宿主中实现细菌存活。该项目的目的是研究沙眼梭菌控制III型分泌和基因表达的机制，从而导致疾病发病机理。我们假设通过分子开关调节T3SS活性在沙眼梭状芽孢杆菌感染过程中，由CT663及其蛋白质伴侣组成。我们的新颖发现，认为衣原体CT663是一种双功能蛋白，既是与含RNA聚合酶相互作用的转录调节剂？ 66和用于COPN的T3SS伴侣，这是调节器和T3SS的效应子。我们的具体目的是：目标1。检验CT663形成III型分泌活性所必需的蛋白质复合物的假设。我们将表征CT663及其伴侣的动态相互作用，以及这些相互作用如何使用定量测定蛋白质蛋白质相互作用，免疫检测和肠病毒性大肠杆菌（EPEC）系统来影响分泌活性。目的2。为了测试CT663差异调节基因转录的假设。这个目标在体外和大肠杆菌中使用我们已建立的转录测定法实现了66RNA聚合酶。这些研究将发现T3SS活性如何影响沙眼梭菌感染期间的基因表达，反之亦然。该项目将通过在感染过程中协调T3SS的调节事件和基因表达的调节事件来提供有关梭状芽孢杆菌如何利用T3S在细胞内生态位中生存的重要见解。我们的研究将显着扩大对沙眼梭状芽胞庭感染过程的当前知识，并有助于鉴定新疗法的潜在药物靶标，这些药物可能会大大减轻由沙眼梭菌感染引起的公共卫生负担。