Mechanisms of Bacterial Toxin Action

细菌毒素作用机制

基本信息

批准号：
7983051
负责人：
Joseph T Barbieri
金额：
$ 34.2万
依托单位：
MEDICAL COLLEGE OF WISCONSIN
依托单位国家：
美国
项目类别：
财政年份：
1990
资助国家：
美国
起止时间：
1990-07-01 至 2015-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7983051
关键词：
ADP Ribose Transferases ADP ribosylation Active Sites Address Bacteria Bacterial Infections Bacterial Toxins Binding Biochemical Biological Bontoxilysin Cell Communication Cell Death Cell membrane Cells Cleaved cell Cultured Cells Cytotoxin Data Detection Development Diagnostic Disease Exotoxins Family Gangliosides Human Individual Infection Lead Measures Membrane Metalloproteases Modeling Modification Molecular Monomeric GTP-Binding Proteins NGFR Protein Neurons Neurotoxins Nosocomial Infections Pathogenesis Pathology Preventive Intervention Property Proteins Pseudomonas aeruginosa Receptor Protein-Tyrosine Kinases Role SNAP receptor Serotyping Signal Transduction Site Site-Directed Mutagenesis Structure Substrate Specificity Subunit Vaccines Techniques Testing Tetanus Toxin Therapeutic Therapeutic Agents Toxin Tube Vesicle Zinc base children with cystic fibrosis insight link protein pathogen prevent public health relevance receptor rho GTP-Binding Proteins rho GTPase-activating protein spastic paralysis tetanospasmin trafficking

项目摘要

DESCRIPTION (provided by applicant): Bacterial pathogens often damage their host through the action of toxins. Bacterial toxins modify host targets, primarily proteins, through covalent and non-covalent mechanisms and have several structure-function organizations, including exotoxins and type III secreted cytotoxins. While exotoxins often act at a distance from the site of infection, type III cytotoxins are delivered directly into the intoxicated host cell by the bacterium. The aims of this application have been to characterize the substrate recognition and intracellular trafficking of bacterial toxins. During the previous period, studies on the type III cytotoxins of Pseudomonas aeruginosa determined substrate recognition mechanisms of ExoS and ExoT and showed that intracellular trafficking within host cells increased the potency of ExoS for Ras and Rho GTPases. A translational project was also developed to detect initial PA infections in humans. This renewal will continue to characterize the intracellular trafficking and substrate recognition on ExoS and initiate structure-function studies on tetanus neurotoxin (TeNT). The proposed studies will characterize specific properties of ExoS and TeNT that define unique aspects of bacterial toxin action. Analyses utilize biochemical- and quantitative cell biological- approaches that allow corroborative analyses from the test tube to the cell. Studies on ExoS will characterize how intracellular trafficking within host cells increases the potency of ExoS and determine the mechanism that ADP-ribosylation inhibits signaling by small GTPases, like Ras and Rab5. Recent studies determined that gangliosides are the functional receptors of TeNT in neurons. This identification allows a fundamental question of neurotoxin pathology to be addressed, how does TeNT elicit spastic paralysis in the host? Studies on TeNT will characterize the intracellular trafficking of TeNT in neurons and determine how TeNT cleaves the SNARE protein, VAMP2. These studies define mechanistic properties of toxins that may lead to translational products for the detection, prevention, and intervention of bacterial infections.

描述（由申请人提供）：细菌病原体经常通过毒素的作用损害其宿主。细菌毒素通过共价和非共价机制修饰宿主靶标（主要是蛋白质），并具有多种结构功能组织，包括外毒素和 III 型分泌细胞毒素。虽然外毒素通常在距离感染部位一定距离处起作用，但 III 型细胞毒素由细菌直接递送到中毒的宿主细胞中。该应用的目的是表征细菌毒素的底物识别和细胞内运输。前期对铜绿假单胞菌III型细胞毒素的研究确定了ExoS和ExoT的底物识别机制，并表明宿主细胞内的细胞内运输增加了ExoS对Ras和Rho GTPases的效力。还开发了一个转化项目来检测人类的初始 PA 感染。这一更新将继续表征 ExoS 的细胞内运输和底物识别，并启动破伤风神经毒素 (TeNT) 的结构功能研究。拟议的研究将表征 ExoS 和 TeNT 的特定特性，这些特性定义了细菌毒素作用的独特方面。分析利用生化和定量细胞生物学方法，可以对从试管到细胞的验证分析。对 ExoS 的研究将表征宿主细胞内的细胞内运输如何增加 ExoS 的效力，并确定 ADP 核糖基化抑制小 GTP 酶（如 Ras 和 Rab5）信号传导的机制。最近的研究确定神经节苷脂是神经元中 TeNT 的功能受体。这一鉴定使得神经毒素病理学的一个基本问题得以解决，即 TeNT 如何引起宿主的痉挛性麻痹？对 TeNT 的研究将表征 TeNT 在神经元中的细胞内运输，并确定 TeNT 如何裂解 SNARE 蛋白 VAMP2。这些研究定义了毒素的机械特性，可能会产生用于检测、预防和干预细菌感染的转化产品。