Molecular Mechanisms Regulating Bacterial Two-component Signaling Systems

调节细菌二组分信号系统的分子机制

基本信息

批准号：
10659547
负责人：
Ernesto Jorge Fuentes
金额：
$ 67.39万
依托单位：
UNIVERSITY OF IOWA
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-02-08 至 2028-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10659547
关键词：
Aerobic Animals Antibiotic Resistance Antibody Formation Bacteria Binding Binding Sites Biochemical Biological Biological Assay Biological Process Catalytic Domain Cell membrane Cells Cessation of life Communities Complex Cryoelectron Microscopy Cysteine Cytoplasm Data Disease Disulfides Drug Metabolic Detoxication Environment Enzymes Fermentation Gene Expression Genes Genus staphylococcus Goals Growth Health Healthcare Heme Hospitals Human Hypoxia Infection Infective endocarditis Integral Membrane Protein Knock-out Length Ligand Binding Ligand Binding Domain Ligands Lipids Membrane Metabolism Methicillin Resistance Microbial Biofilms Modeling Molecular Molecular Conformation Morbidity - disease rate N-terminal Nitric Oxide OmpR protein Osteomyelitis Output Oxidation-Reduction Oxidative Stress Oxygen Pathogenicity Phosphorylation Phosphotransferases Physiology Pneumonia Publishing Regulation Regulon Role Sepsis Signal Pathway Signal Transduction Site Site-Directed Mutagenesis Societies Staphylococcal Infections Staphylococcus aureus Staphylococcus aureus infection Stimulus System Systemic infection Testing Variant Virulence Virulence Factors Vitamin K 2 X-Ray Crystallography biophysical techniques combat cost design enzyme activity extracellular genetic approach global health in vivo inhibitor insight methicillin resistant Staphylococcus aureus mortality mouse model nanodisk nanoscale nitrosative stress novel therapeutic intervention novel therapeutics protein-histidine kinase reconstitution respiratory response sensor histidine kinase small molecule small molecule libraries transmission process treatment strategy

项目摘要

PROJECT SUMMARY/ABSTRACT Staphylococcus aureus infections are a major global health problem and remain a significant health burden to society. In the U.S. alone it is estimated that over three-hundred thousand cases of hospital-associated S. aureus infections occur yearly at the cost of $2 billion. These infections also contribute to pneumonia, sepsis, infective endocarditis, osteomyelitis, and other diseases. S. aureus infections and associated diseases result from secreted virulence factors and the ability of the bacterium to survive in a wide range of environmental niches, including hypoxic conditions. Importantly, growth and virulence are regulated by two-component systems (TCS), which are composed of a membrane-bound sensor histidine kinase (HK) and a cytoplasmic response regulator protein. The kinase senses the extracellular environment, and under the appropriate stimuli transmits a signal across the cell membrane to induce phosphorylation of the response regulator, resulting in changes in gene expression. The staphylococcus respiratory response AB (SrrAB) TCS is activated under hypoxic conditions or in the presence of nitrosative stress and coordinates the regulation of virulence factors, fermentation enzymes, nitric oxide detoxifying enzymes and biofilm formation. In this proposal, the PI will pursue three aims designed to reveal the regulatory mechanisms of the SrrB sensor histidine kinase. The SrrB HK is a transmembrane protein that contains an N-terminal extracellular Cache domain and a cytoplasmic catalytic region (HAMP-PAS-DHpCA) containing a PAS domain. The first aim is to determine the role of the SrrB PAS domain and how binding to heme impacts SrrB function. The second aim will identify ligands that bind to the Cache domain and elucidate its sensing mechanism and role in virulence. The third aim will determine the structural basis for SrrB enzymatic regulation using X-ray crystallography, SAXS and cryogenic electron microscopy of full-length SrrB reconstituted in nanometer-scale lipid discs. Successful completion of these studies will provide the molecular mechanism(s) by which SrrB senses extracellular ligands and cellular redox to regulate catalytic function, and the biological consequences for disrupting this regulation. Our results will have important implications for the design of novel therapeutic strategies targeting the SrrAB TCS to combat antibiotic resistant S. aureus strains.

项目摘要/摘要金黄色葡萄球菌感染是一个主要的全球健康问题，仍然是重大健康负担社会。仅在美国，据估计，超过三十万例医院相关。金黄色的感染每年以20亿美元的价格发生。这些感染也导致肺炎，败血症，感染性心内膜炎，骨髓炎和其他疾病。金黄色葡萄球菌感染和相关疾病结果从分泌的毒力因子和细菌在各种环境中生存的能力利基，包括低氧条件。重要的是，生长和毒力受到两个组件的调节系统（TC），由膜结合的传感器组氨酸激酶（HK）和细胞质组成响应调节蛋白。激酶感应细胞外环境，并在适当的刺激下感应在细胞膜上传输信号以诱导响应调节剂的磷酸化，从而导致基因表达的变化。葡萄球菌呼吸反应AB（SRRAB）TC在下方激活低氧条件或硝化应激的存在，并协调毒力因子的调节，发酵酶，一氧化氮排毒酶和生物膜形成。在此提案中，PI将追求三个目的旨在揭示SRRB传感器组氨酸激酶的调节机制。 SRB HK是一种跨膜蛋白，含有N末端的细胞外缓存结构域和细胞质包含PAS结构域的催化区域（HAMP-PAS-DHPCA）。第一个目的是确定 SRRB PAS结构域以及与血红素的结合如何影响SRRB功能。第二个目标将确定配体与缓存结构域结合并阐明其感应机制和在毒力中的作用。第三个目标使用X射线晶体学，SAXS和低温确定SRRB酶调节的结构基础全长SRRB的电子显微镜在纳米尺度脂质盘中重构。成功完成这些研究将提供分子机制，SRRB感受细胞外配体和细胞氧化还原以调节催化功能，以及破坏该调节的生物学后果。我们的结果将针对SRRAB TCS的新型治疗策略的设计具有重要意义战斗抗生素抗生素金黄色葡萄球菌菌株。