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.

项目概要/摘要金黄色葡萄球菌感染是一个主要的全球健康问题，并且仍然是一个重大的健康负担社会。据估计，仅在美国就有超过三十万例与医院相关的金黄色葡萄球菌病例。金黄色葡萄球菌感染每年造成 20 亿美元的损失。这些感染还会导致肺炎、败血症、感染性心内膜炎、骨髓炎等疾病。金黄色葡萄球菌感染和相关疾病的结果来自分泌的毒力因子和细菌在各种环境中生存的能力生态位，包括缺氧条件。重要的是，生长和毒力由两种成分调节系统（TCS），由膜结合传感器组氨酸激酶（HK）和细胞质反应调节蛋白。激酶感知细胞外环境，并在适当的刺激下跨细胞膜传递信号以诱导反应调节剂磷酸化，从而导致基因表达的变化。葡萄球菌呼吸反应 AB (SrrAB) TCS 在以下条件下被激活缺氧条件或存在亚硝化应激并协调毒力因子的调节，发酵酶、一氧化氮解毒酶和生物膜形成。在本提案中，PI 将追求三个目标，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，包含 N 端细胞外 Cache 结构域和细胞质含有 PAS 结构域的催化区 (HAMP-PAS-DHpCA)。第一个目标是确定 SrrB PAS 结构域以及与血红素的结合如何影响 SrrB 功能。第二个目标是确定配体结合到缓存域并阐明其感知机制和在毒力中的作用。第三个目标将使用 X 射线晶体学、SAXS 和低温确定 SrrB 酶促调节的结构基础在纳米级脂质盘中重建的全长 SrrB 的电子显微镜。顺利完成这些研究将提供 SrrB 感知细胞外配体和细胞内配体的分子机制。氧化还原调节催化功能，以及破坏这种调节的生物学后果。我们的成果将对针对 SrrAB TCS 的新型治疗策略的设计产生重要影响对抗抗生素耐药性金黄色葡萄球菌菌株。