Integration of heme acquisition and signaling in Gram-negative pathogens

革兰氏阴性病原体中血红素获取和信号传导的整合

• 批准号: 10591561
• 负责人: Amanda Gail Oglesby
• 金额: $ 48.05万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10591561
• 关键词: Accounting; Aerobic; Affect; Anti-Bacterial Agents; Antibiotic Resistance; Bacterial Infections; Binding; Binding Proteins; Biochemical; Biological Process; Biophysics; Cells; Cessation of life; Citric Acid Cycle; Cytoplasm; DNA; DNA biosynthesis; Data; Drug resistance; EMSA; ESKAPE pathogens; Event; Fluorescence Anisotropy; Future; Gene Expression; Genes; Genetic; Genetic Transcription; Genetic study; Goals; Heme; Homeostasis; Homologous Gene; Infection; Iron; Klebsiella pneumoniae; Laboratories; Life; Link; Membrane; Metabolism; Methods; Microbial Biofilms; Micronutrients; Molecular; Mutation; Mycoses; Oxidation-Reduction; Oxidative Stress; Oxygenases; Peptide Hydrolases; Post-Transcriptional Regulation; Property; Proteins; Proteomics; Pseudomonas aeruginosa; Public Health; RNA; RNA Binding; RNA chemical synthesis; Regulation; Regulon; Reporting; Respiration; Role; Shigella dysenteriae; Siderophores; Signal Transduction; Site-Directed Mutagenesis; System; Testing; Time; Toxin; Transcriptional Regulation; Up-Regulation; Uropathogenic E. coli; Variant; Virulence; Virulence Factors; antimicrobial; antimicrobial resistant pathogen; antitermination; biochemical tools; biophysical techniques; biophysical tools; chronic infection; constitutive expression; enteric pathogen; extracellular; genetic regulatory protein; heme-binding protein; human pathogen; in vivo; innovation; mRNA Transcript Degradation; microorganism; new therapeutic target; novel therapeutic intervention; pathogen; pathogenic bacteria; pathogenic microbe; posttranscriptional; promoter; receptor; rho; trait; transcription regulatory network; uptake

PROJECT SUMMARY ESKAPE pathogens are a leading cause of drug resistant infections and the need to identify new antibacterial strategies is critical. Iron is an essential micronutrient for survival and virulence that microbial pathogens which actively sequesters iron away from microorganisms. Pathogens overcome this iron limitation through a variety of mechanisms, including the synthesis and secretion of siderophores that scavenge ferric (Fe3+) iron, the uptake of ferrous (Fe2+) iron via Feo or NRAMP-like systems, and acquisition of iron from host heme. iron acquisition and homeostasis by microbial pathogens is multifactorial and dependent on sophisticated transcriptional and post-transcriptional regulatory networks. We have recently shown the PhuS cytoplasmic heme binding protein has a dual function in regulating heme flux through HemO, and in the transcriptional regulation of the iron and heme regulated sRNA’s PrrF and PrrH. The PrrF sRNAs bind to complementary sequences of their target RNAs causing the RNAseE and Hfq-dependent mRNA degradation of genes involved in iron-storage and oxidative stress, aerobic and anaerobic metabolism, including iron containing proteins of the TCA cycle, as well as several virulence factors. Therefore, regulation of the heme flux through HemO is a critical link between heme metabolism and the iron-dependent sRNA regulatory network required for adaptation and virulence within the host. The goal of the proposal is to understand at a molecular level how heme acquisition is integrated into these regulatory networks. Specifically, we will; i) determine the PhuS structural motifs required for heme transfer and binding to the prrF1 promoter (PprrF1), ii) define the in vivo effects of PhuS variants on PrrF/H sRNAs and the downstream regulon. and iii) determine evolutionary conservation and function of PhuS homologs across enteric pathogens. On completion of the studies we will have determined the role of extracellular heme metabolism in the iron-dependent regulatory networks of three significant human pathogens, providing a platform for the identification of antibacterial strategies at the interface between of iron homeostasis and virulence.

项目摘要 Eskape病原体是耐药感染的主要原因，需要鉴定新的抗菌 策略至关重要。铁是微生物病原体的生存和病毒的必不可少的微量营养素 积极地隔离铁远离微生物。病原体克服了这种铁的限制 机理的合成和分泌，包括清除铁（Fe3+）铁的铁载体 通过FEO或NRAMP样系统吸收亚铁（Fe2+）铁，并从宿主血红素中获取铁。铁 微生物病原体的获取和稳态是多因素的，并且取决于复杂的 转录和转录后调节网络。我们最近显示了细胞质的phus 血红素结合蛋白在调节血红素通量通过血液中具有双重功能，在转录中 铁和血红素调节的调节SRNA的PRRF和PRRH。 PRRF SRNA结合到完成 靶RNA的序列引起涉及的rnAsee和HFQ依赖性mRNA降解 在铁的储存和氧化应激中，有氧和厌氧代谢，包括含有蛋白质的铁 TCA周期以及几个病毒因素。因此，血红素通过血红素的调节是一个 血红素代谢与铁依赖性的SRNA调节网络之间的关键联系 宿主内的适应性和病毒。该提议的目的是在分子层中了解如何 血红素获取已集成到这些监管网络中。具体来说，我们将； i）确定phus 血红素转移并结合到PRF1启动子（PPRF1），ii）定义体内所需的结构基序 PHUS变体对PRRF/H SRNA和下游调节的影响。 iii）确定进化 跨肠病原体的Phus同源物的保护和功能。完成研究后，我们将 已经确定了细胞外血红素代谢在三个的铁依赖性调节网络中的作用 重要的人类病原体，为鉴定抗菌策略的平台提供了一个平台 铁稳态与病毒之间的接口。