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: 8609131
• 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/8609131
• 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.

摘要 微生物之间的共生相互作用在自然界中是丰富的。基因的不寻常组合， 研究这些相互作用所需的生物化学和化学技术阻碍了它们的详细研究。 分析，因此，大多数人仍然没有得到很好的检查。地球上资源最丰富， 重要的共生现象发生在海洋中的微生物之间，如Emiliania huxleyi和海洋中的细菌。 蔷薇属分支，如加拉茨棕。E. huxleyi占据了所有阳光照射的海洋层并玩耍 在全球氧和碳循环中扮演重要角色。它形成了大量的季节性开花， 间歇性地与蔷薇科分支的成员联系。玫瑰花在沿海地区随处可见 并在全球硫循环中发挥重要作用。虽然玫瑰菌-藻类共生体驱动了许多 在地球化学过程中，这些相互作用背后的分子原理仍然未知。我们 初步结果表明，根据不同的情况，P. gallaeciensis产生了一种有效的，新的 代谢产物，杀死大肠杆菌。huxleyi。拟议的研究计划旨在1）发现全球监管机构和小型 介导或调节玫瑰杆菌-藻类相互作用的分子信号，2）使用基于NMR的方法， 表征由蔷薇科植物响应藻类信号产生的次级代谢产物的结构，以及 使用生物测定来确定它们的功能，3）通过以下方式描绘这些代谢物的生物合成途径： 转座子诱变、基因缺失和酶促研究，以及4）揭示代谢产物的产生是如何 使用遗传和生物化学方法的组合进行调节。随后，这些研究将 扩展到其他玫瑰花研究的一般性原则发现与E。huxleyi和黑胸叶蝉P. 加拉茨这项研究计划将产生所需的工具，以表征许多类似的环境 重要的互动。因为共生体含有一个未被开发的代谢物库， 在制药和/或农业应用中，该提议还可以鉴定新的和有用的分子。 哈佛医学院在这一领域或工作中提供了一个智力利基和一个既定的研究计划。 它由天然产物化学和细菌遗传学领域的领导者组成，他们将担任我的 项目中的导师。获得机械酶学博士学位后，我的短期目标是 是为了获得必要的技能，以检查微生物共生的各个方面。在辅导 在第一阶段，我将接受细菌遗传学、小分子表征和相关生物测定方面的培训。期间 这一次，我还将参加一个先进的细菌遗传学课程和其他研讨会/会议，学习 成为一名成功的PI所需的科学技术和管理技能。在独立阶段， 这些方法将被用来揭示代谢产物的产生和检查生物合成的调节。 内切酶从长远来看，我计划在一个学术机构领导一个多学科的研究项目， 研究对环境重要的共生体的基本化学、酶学和生物学。