Molecular Analysis of Metabolites and Signaling Networks in Microbial Symbioses

微生物共生中代谢物和信号网络的分子分析

• 批准号: 8627615
• 负责人: Mohammad R Seyedsayamdost
• 金额: $ 24.9万
• 依托单位: PRINCETON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-25 至 2016-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8627615
• 关键词: Address; Agriculture; Algae; Anabolism; Anti-Bacterial Agents; Area; Bacteria; Biochemical; Biological; Biological Assay; Biological Models; Biological Process; Biology; Carbon; Cell Wall; Chemicals; Chemistry; Cues; Data; Doctor of Philosophy; Educational workshop; Enzymatic Biochemistry; Enzymes; Gene Cluster; Gene Deletion; Gene Fusion; Generations; Genetic; Genetic Screening; Goals; Hybrids; In Vitro; Institution; Interdisciplinary Study; Isotopes; Lead; Learning; Libraries; Lignin; Mediating; Mentors; Methods; Microscopic; Modeling; Molecular; Molecular Analysis; Mutagenesis; Natural Products Chemistry; Nature; Oceans; Oxygen; Pathway interactions; Pharmaceutical Preparations; Pharmacologic Substance; Phase; Plants; Play; Process; Production; Property; Regulation; Research; Role; Roseobacter; Signal Transduction; Signaling Molecule; Source; Structure; Sulfur; Symbiosis; System; Techniques; Testing; The Sun; Time; Training; Virulence; Work; abstracting; bacterial genetics; base; homoserine lactone; improved; killings; medical schools; member; microbial; microorganism; mutant; novel; pathogen; programs; quorum sensing; research study; response; screening; senescence; skills; small molecule; symposium; tool

Abstract Symbiotic interactions among microorganisms are abundant in nature. The unusual combination of genetic, biochemical and chemical techniques required to study these interactions has hampered their detailed analysis, and therefore most remain poorly-examined. One of the most abundant and environmentally important symbioses occurs in the oceans between microscopic alga, like Emiliania huxleyi, and bacteria of the roseobacter clade, such as Phaeobacter gallaeciensis. E. huxleyi occupies all sun-lit ocean layers and plays an important role in global oxygen and carbon cycles. It forms massive seasonal blooms, where it intermittently associates with members of the roseobacter clade. Roseobacter are ubiquitous in coastal areas and play a major role in global sulfur cycles. While roseobacter-algal symbioses drive numerous biogeochemical processes, the molecular principles underlying these interactions remain unknown. Our preliminary results have shown that P. gallaeciensis, depending on circumstances, produces a potent, novel metabolite that kills E. huxleyi. The proposed research plan aims to 1) discover global regulators and small molecule signals that mediate or modulate roseobacter-algal interactions, 2) use NMR-based methods to characterize the structures of secondary metabolites produced by roseobacter in response to algal signals, and use bioassays to determine their functions, 3) delineate the biosynthetic pathway of these metabolites by transposon mutagenesis, gene deletions, and enzymatic studies, and 4) uncover how metabolite production is regulated using a combination of genetic and biochemical approaches. Subsequently, these studies will be extended to other roseobacter to examine the generality of the principles uncovered with E. huxleyi and P. gallaeciensis. This research plan will generate the tools needed to characterize many similar environmentally important interactions. Because symbioses contain a poorly-explored reservoir of metabolites with potential pharmaceutical and/or agricultural applications, this proposal could also identify novel and useful molecules. Harvard Medical School offers an intellectual niche and an established research program in this area or work. It consists of leaders in the fields of natural products chemistry and bacterial genetics who will serve as my mentors in the proposed project. Having obtained my PhD in mechanistic enzymology, my short-term goals are to acquire the skills necessary to examine the various aspects of microbial symbioses. In the mentored phase, I will be trained in bacterial genetics, small molecule characterization and relevant bioassays. During this time, I will also attend an advanced bacterial genetics course and other workshops/conferences to learn the scientific techniques and management skills required to be a successful PI. In the independent phase, these methods will be used to uncover the regulation of metabolite production and to examine the biosynthetic enzymes. In the long-term, I plan to lead a multidisciplinary research program in an academic institution to study the underlying chemistry, enzymology and biology of environmentally important symbioses.

抽象的 微生物之间的共生相互作用本质上很丰富。遗传的异常组合， 研究这些相互作用所需的生化和化学技术阻碍了它们的详细信息 分析，因此大多数仍然存在较差的情况。最丰富和环境的 重要的共生物发生在微观藻类之间的海洋中 玫瑰杆菌（Roseobacter），例如phaeobacter gallaeciensis。 E. Huxleyi占据了所有阳光阳光的海洋层 在全球氧气和碳周期中的重要作用。它形成了巨大的季节性开花 间歇性地与Roseobacter进化枝的成员联系。玫瑰杆菌在沿海地区无处不在 并在全球硫循环中发挥重要作用。而玫瑰杆菌 - 阿尔加尔共生型驱动了无数 生物地球化学过程，这些相互作用基础的分子原理仍然未知。我们的 初步结果表明，gallaeciensis取决于情况，会产生有效的新颖 杀死E. Huxleyi的代谢产物。拟议的研究计划的目的是1）发现全球监管机构和小 介导或调节roseobacter-Algal相互作用的分子信号，2）使用基于NMR的方法 表征玫瑰杆菌对藻类信号产生的二级代谢产物的结构，以及 使用生物测定来确定其功能，3）描绘这些代谢物的生物合成途径 转座子诱变，基因缺失和酶学研究，以及4）发现代谢物的产生方式 使用遗传和生化方法的组合来调节。随后，这些研究将是 扩展到其他玫瑰杆菌，以检查与E. Huxleyi和P.发现的原则的一般性。 Gallaeciensis。该研究计划将生成在环境上表征许多类似类似的工具 重要的互动。因为共生物包含一个潜在的代谢物的探索储备不佳 该提案还可以识别出新颖且有用的分子。 哈佛医学院在这一领域或工作中提供了知识分裂和既定的研究计划。 它由天然产品化学和细菌遗传学领域的领导者组成，这些领域将作为我 拟议项目的导师。在机械酶学上获得了我的博士学位，我的短期目标 是要获得检查微生物共生的各个方面所需的技能。在指导中 阶段，我将接受细菌遗传学，小分子表征和相关生物测定的训练。期间 这次，我还将参加先进的细菌遗传学课程和其他研讨会/会议来学习 成功的PI需要科学技术和管理技能。在独立阶段， 这些方法将用于发现代谢产物的调节并检查生物合成 酶。从长远来看，我计划领导学术机构的多学科研究计划 研究环境重要共生的基本化学，酶学和生物学。