Integrating Global Responses to Nutrient Limitation in Gram-positive Bacteria

整合全球对革兰氏阳性菌营养限制的反应

• 批准号: 8737911
• 负责人: Shaun R Brinsmade
• 金额: $ 24.21万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8737911
• 关键词: Affect; Amino Acids; Award; Bacillus subtilis; Bacteria; Bacterial Infections; Bacterial Physiology; Behavior; Benign; Binding; Biochemical; Biochemistry; Branched-Chain Amino Acids; Calculi; Cells; Development; Disease; Foundations; Funding; Gene Expression; Gene Expression Profile; Genes; Genetic; Goals; Gram-Positive Bacteria; Guanine Nucleotides; Guanosine Triphosphate; Health; Heart; Human; Human body; In Vitro; Infection; Isoleucine; Knowledge; Laboratories; Lead; Learning; Leucine; Life; Life Style; Maps; Mass Spectrum Analysis; Massive Parallel Sequencing; Measures; Mediating; Mentors; Metabolic; Metabolism; Methods; Mission; Modeling; Monitor; National Institute of General Medical Sciences; Nosocomial Infections; Nutrient; Output; Pathogenesis; Pathway interactions; Phase; Physiological; Physiology; Process; Public Health; Regulation; Regulon; Research; Research Personnel; Resources; Role; Route; Signal Transduction; Soil; Staphylococcus aureus; System; Systems Biology; Techniques; Therapeutic; Time; Training; Universities; Valine; Variant; Virulence; abstracting; antimicrobial; base; biological adaptation to stress; career; career development; design; environmental change; exhaustion; functional genomics; genetic manipulation; in vivo; innovation; medical schools; metabolomics; novel; novel therapeutics; nucleoside triphosphate; pathogen; prevent; programs; promoter; research and development; research study; response; tool; transcription factor

7. Project Summary/Abstract. Expression of bacterial virulence genes often correlates with the exhaus- tion of nutrients, but how the signaling of nutrient availability and the resulting physiological responses are co- ordinated is unclear. Until this gap in knowledge is closed, metabolically diverse bacteria like Staphylococcus aureus will continue to cause perilous hospital-acquired infections. The applicant's long-term goal is to lead an independent academic research group studying how bacteria integrate and respond to information provided by intracellular metabolites (the metabolome) to reconfigure metabolism to adapt to environmental changes and cause disease. The objective of this project is to augment existing genetic and biochemical expertise with high- throughput global techniques to analyze gene expression, intracellular metabolites and flux, and, in doing so, titrate the activity of the global regulator CodY and deduce its regulatory hierarchy in S. aureus. At the heart of this project is the hypothesis that fluctuations in the intracellular pools of branched-chain amino acids and GTP result in a spectrum of CodY activities that produce a graded response to nutrient limitation, culminating in metabolic adaptation and the development of virulence. This hypothesis is based on preliminary studies that identified the true intracellular metabolites that control CodY activity in living cells and revealed hierarchical or- ganization for three genes. The rationale for this project is that comprehensive knowledge of the co-regulation of metabolism and virulence is essential if we are to understand the physiological origins of bacterial patho- genesis. During the mentored (K99) phase at Tufts University School of Medicine, massively parallel sequenc- ing, mass spectrometry-based metabolomics and chemostat cultivation will be mastered to map intersecting metabolic and virulence gene expression patterns in S. aureus, while gaining critical scholarly training needed to launch a successful independent academic career with guidance from a mentoring committee composed of experts in bacterial physiology, biochemistry and systems biology. Mastering the cultivation and genetic ma- nipulation of pathogenic S. aureus along with high-throughput methods will enable efforts during the R00 phase to quantify changes in the S. aureus CodY regulon upon induction of physiological stress response sys- tems. The approach is innovative, because continuous bacterial cultures mimic nutrient-limiting bacterial nich- es in the human body and the experiments will place virulence gene expression in the context of the normal behavior of S. aureus under the nutrient-limiting conditions of the host. Furthermore, correlations between global metabolite pools and CodY activity will provide a previously unattainable linkage of the transcriptome to the metabolome. The project is significant because it will increase our understanding of how the genetic pro- grams of metabolic adaptation and virulence gene expression are interrelated and interdependent. A more thorough understanding of these connections may also offer potentially novel therapeutic strategies. The Pathway to Independence Award will provide the time and resources needed to achieve these goals.

7。项目摘要/摘要。细菌毒力基因的表达通常与exhaus- 营养素的含量，但是营养物的信号传导和由此产生的生理反应是如何共同的 训练尚不清楚。直到封闭知识的差距，代谢多样的细菌（如葡萄球菌） 金银将继续引起危险的医院获得感染。申请人的长期目标是领导 独立的学术研究小组研究细菌如何整合和响应由 细胞内代谢物（代谢组）重新配置代谢以适应环境变化和 引起疾病。该项目的目的是增加具有高度的遗传和生化专业知识 吞吐全局技术以分析基因表达，细胞内代谢产物和通量，并且这样做， 滴定全球调节剂Cody的活性，并在金黄色葡萄球菌中推断其监管层次结构。核心 该项目是一个假设，即分支链氨基酸和GTP的细胞内池的波动 导致一系列CODY活性产生对营养限制的分级反应，最终导致 代谢适应和毒力的发展。该假设基于初步研究 确定了控制活细胞中Cody活性的真正细胞​​内代谢产物，并揭示了分层或 三个基因的ganization。该项目的理由是对共同调节的全面知识 如果我们要了解细菌病原体的生理起源，代谢和毒力至关重要 创世纪。在塔夫茨大学医学院的指导阶段（K99）阶段，很大程度上平行的序列 ING，基于质谱的代谢组学和化学固化培养将掌握以绘制相交 金黄色葡萄球菌中的代谢和毒力基因表达模式，同时需要获得关键的学术训练 在一个由指导委员会的指导下启动成功的独立学术职业 细菌生理，生物化学和系统生物学专家。掌握培养和遗传学 致病性金黄色葡萄球菌以及高通量方法将在R00期间努力努力 在诱导生理应力反应系统时，量化金黄色葡萄球菌调节的变化的阶段 tems。这种方法是创新的，因为连续细菌培养物模仿了限制营养的细菌元素。 ES在人体中，实验将在正常情况下放置毒力基因表达 金黄色葡萄球菌在宿主的营养限制条件下的行为。此外，之间的相关性 全球代谢物池和Cody活动将为转录组提供以前无法实现的联系 代谢组。该项目很重要，因为它将加深我们对遗传促进的理解 代谢适应和毒力基因表达的克克是相互关联和相互依存的。更多 对这些联系的透彻理解也可能提供潜在的新型治疗策略。这 独立奖的途径将为实现这些目标提供所需的时间和资源。