Mechanisms of Bacterial Toxin Action

细菌毒素作用机制

基本信息

批准号：
8470515
负责人：
Joseph T Barbieri
金额：
$ 31.83万
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/8470515
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 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）：细菌病原体通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，并具有几个结构功能组织，包括外毒素和III型分泌细胞毒素。虽然外毒素通常与感染部位起作用，但III型细胞毒素被细菌直接输送到陶醉的宿主细胞中。该应用的目的是表征细菌毒素的底物识别和细胞内运输。在上一个时期，对铜绿假单胞菌的III型细胞毒素的研究确定了外构和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RAS和Rho GTPases的Exos的效力。还开发了一个转化项目，以检测人类的初始PA感染。这种更新将继续表征外部的细胞内贩运和底物识别，并启动对破伤风神经毒素（帐篷）的结构 - 功能研究。拟议的研究将表征Exos和帐篷的特定特性，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，可以从试管到细胞进行佐证分析。关于EXOS的研究将表征宿主细胞内的细胞内运输如何增加外来的效力，并确定ADP-核糖基化抑制小GTPase（如RAS和RAB5）的信号传导的机制。最近的研究确定神经毒剂是神经元中帐篷的功能受体。这种鉴定允许解决神经毒素病理学的基本问题，帐篷如何引起宿主的痉挛性麻痹？关于帐篷的研究将表征神经元中帐篷的细胞内运输，并确定帐篷如何裂解SNARE蛋白VAMP2。这些研究定义了毒素的机械性能，这些特性可能导致细菌感染的检测，预防和干预的转化产物。