The role of metal ion homeostasis in regulating bacterial capsule production

项目摘要/摘要 由病原菌产生的荚膜多糖(CPS)是决定致病性的关键因素 细菌在人类宿主中存活，但对CPS生产如何调控的了解仍然有限。vt.给出 病原菌需要在不同的寄主生态位中调节CPS的表达(厚度) 疾病的进展，我们在这里假设可用的环境因素，如金属离子微量营养素 会影响CPS的生产。长期目标是帮助开发替代的金属抗菌剂 临床治疗人类细菌性疾病的治疗学。本申请的总体目标是， 这构成了实现长期目标的第一步，就是识别分子 细胞金属离子比率，特别是锰(锰)、锌(锌)和钙(钙)， 影响CPS的生产，同时增加本科生对研究的接触并提高爱达荷州的水平 州立大学的生物医学研究企业。中心假设是金属离子微量营养素 利用链球菌直接调节病原菌的酶活性调控CPS的生物发生 肺炎杆菌(Spn)为革兰氏阳性模式菌。这个项目的基本原理是一个机械论的 了解细胞金属离子比例如何调节CPS表达水平将提供新的机会 用于随后确定和制定用于设计新的治疗干预措施的目标 人类致病细菌感染。为实现总体目标，我们将具体落实以下几个方面 目标：1)确定生物有效锰/锌比例影响CPS产量的机制(S)；2)确定 钙在锰动态平衡和CPS生物发生中的作用第一个目标将评估生理和 生物可利用锰/锌比对红豆杉几种利用锰酶的生化影响 Spn CPS的生物合成途径。第二个目标是评估钙/锰比对细胞内的影响。 金属景观和CPS的生物合成与RNAseq和蛋白质组分析相协调。整体而言 方法将经典微生物学技术与现代应用程序相结合，这些应用程序跨越了 生物和化学，从而使本科生接触到跨学科的研究技术。这个 申请人认为，本申请中提出的研究是创新的，因为它代表了一种 通过关注整体细胞金属离子微量营养素的影响，实质性地偏离现状 比率及其调节细菌CPS生物发生的能力。拟议的研究还将进一步推动 了解细胞内金属离子的有效性如何作为影响全球细胞的信号因子 发病过程中的变化和细胞编程。这项拟议的研究具有重要意义，因为它 有望为未来机械和替代金属的设计提供坚实的基础- 基于药物开发的战略，以对抗容易表现出多药的人类细菌病原体 抵抗。

Project Summary/Abstract Capsular polysaccharide (CPS) produced by pathogenic bacteria is a key virulence determinant for bacterial survival in the human host, but knowledge of how CPS production is regulated remains limited. Given the need for pathogenic bacteria to modulate CPS expression (thickness) among various host niches during disease progression, we postulate here that available environmental factors such as metal ion micronutrients can influence CPS production. The long-term goal is to help develop alternative metal-based antimicrobial therapeutics for clinical treatment of bacterial diseases in humans. The overall objectives in this application, which constitute the first step toward attainment of the long-term goal, are to identify the molecular mechanisms by which cellular metal ion ratios, specifically manganese (Mn), zinc (Zn), and calcium (Ca), influence CPS production, while increasing exposure of undergraduates to research and enhancing Idaho State University’s biomedical research enterprise. The central hypothesis is that metal ion micronutrients regulate CPS biogenesis via direct modulation of enzyme activity in pathogenic bacteria using Streptococcus pneumoniae (Spn) as a Gram-positive model bacterium. The rationale for this project is that a mechanistic understanding of how cellular metal ion ratios regulate CPS expression levels would provide new opportunities for the subsequent identification and development of targets for the design of novel interventions to treat human pathogenic bacterial infections. To attain the overall objectives, we will pursue the following specific aims: 1) Identify the mechanism(s) whereby bioavailable Mn/Zn ratios affect CPS production; and 2) Determine the role of Ca in Mn homeostasis and CPS biogenesis. The first aim will assess the physiological and biochemical impact of bioavailable Mn/Zn ratios on several Mn-utilizing enzymes involved in various arms of the Spn CPS biosynthetic pathway. The second aim will assess the impact of Ca/Mn ratios on the intracellular metal landscape and CPS biosynthesis in coordination with RNAseq and proteomic analysis. The overall approach combines classical microbiology techniques with modern day applications that span the interface of biology and chemistry, thereby exposing undergraduates to interdisciplinary research techniques. The research proposed in this application is innovative, in the applicant’s opinion, because it represents a substantive departure from the status quo by focusing on the impact of overall cellular metal ion micronutrient ratios and their capacity to regulate bacterial CPS biogenesis. The research proposed will also further the understanding of how cellular metal ion availability serve as signaling factors that influence global cellular changes and cellular programing during pathogenesis. The proposed research is significant because it is expected to provide a strong foundation for subsequent future design of mechanistic and alternative metal- based drug development strategies to combat human bacterial pathogens prone to exhibiting multidrug resistance.