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: 8306940
• 负责人: Mohammad R Seyedsayamdost
• 金额: $ 4.49万
• 依托单位: HARVARD MEDICAL SCHOOL
• 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 2012-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8306940
• 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; Screening procedure; Signal Transduction; Signaling Molecule; Source; Structure; Sulfur; Symbiosis; System; Techniques; Testing; The Sun; Time; Training; Virulence; Work; bacterial genetics; base; homoserine lactone; improved; killings; medical schools; member; microbial; microorganism; mutant; novel; pathogen; programs; quorum sensing; research study; response; senescence; skills; small molecule; symposium; tool

DESCRIPTION (provided by applicant): 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.

描述（由申请人提供）：自然界中微生物之间的共生相互作用非常丰富。研究这些相互作用所需的遗传、生化和化学技术的不寻常组合阻碍了他们的详细分析，因此大多数仍然没有得到充分的检查。最丰富且对环境最重要的共生关系之一发生在海洋中的微小藻类（如赫胥氏艾米利亚藻）和玫瑰杆菌分支的细菌（如加氏褐杆菌）之间。赫胥黎桉占据了所有阳光照射的海洋层，在全球氧和碳循环中发挥着重要作用。它形成大规模的季节性开花，并间歇性地与玫瑰杆菌分支的成员结合。玫瑰杆菌在沿海地区普遍存在，在全球硫循环中发挥着重要作用。虽然玫瑰杆菌-藻类共生驱动了许多生物地球化学过程，但这些相互作用背后的分子原理仍然未知。我们的初步结果表明，加拉氏原虫根据具体情况产生一种有效的新型代谢物，可以杀死赫胥黎原虫。拟议的研究计划旨在 1) 发现介导或调节 Roseobacter-藻类相互作用的全局调节因子和小分子信号，2) 使用基于 NMR 的方法来表征 Roseobacter 响应藻类信号产生的次级代谢产物的结构，并使用生物测定为了确定它们的功能，3）通过转座子诱变、基因删除和酶学研究描绘这些代谢物的生物合成途径，4）揭示如何代谢产物的产生是通过遗传和生化方法的结合来调节的。随后，这些研究将扩展到其他玫瑰杆菌，以检验赫胥黎埃球菌和高卢玫瑰杆菌所揭示原理的普遍性。该研究计划将产生描述许多类似的对环境重要的相互作用所需的工具。由于共生体含有尚未开发的代谢物库，具有潜在的制药和/或农业应用，因此该提议还可以识别新颖且有用的分子。哈佛医学院在该领域或工作中提供知识利基和既定的研究计划。它由天然产物化学和细菌遗传学领域的领导者组成，他们将在拟议项目中担任我的导师。获得机械酶学博士学位后，我的短期目标是获得检查微生物共生的各个方面所需的技能。在指导阶段，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。在此期间，我还将参加高级细菌遗传学课程和其他研讨会/会议，以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，这些方法将用于揭示代谢物产生的调节并检查生物合成酶。从长远来看，我计划在学术机构领导一个多学科研究项目，研究对环境重要的共生体的基础化学、酶学和生物学。

项目成果

Investigation of the Genetics and Biochemistry of Roseobacticide Production in the Roseobacter Clade Bacterium Phaeobacter inhibens.

玫瑰杆菌分支细菌抑制褐杆菌中玫瑰杀菌剂生产的遗传学和生物化学研究。

• 发表时间: 2016-03-22
• 影响因子: 6.4
• 作者: Wang, Rurun;Gallant, Étienne;Seyedsayamdost, Mohammad R
• 通讯作者: Seyedsayamdost, Mohammad R

Long-range proton-coupled electron transfer in the Escherichia coli class Ia ribonucleotide reductase.

大肠杆菌 Ia 类核糖核苷酸还原酶中的长程质子耦合电子转移。

• 发表时间: 2017-05-09
• 作者: Reece, Steven Y;Seyedsayamdost, Mohammad R
• 通讯作者: Seyedsayamdost, Mohammad R

Genomes and virulence factors of novel bacterial pathogens causing bleaching disease in the marine red alga Delisea pulchra.

引起海洋红藻 Delisea pulchra 白化病的新型细菌病原体的基因组和毒力因子。

• 发表时间: 2011
• 影响因子: 3.7
• 作者: Fernandes, Neil;Case, Rebecca J;Longford, Sharon R;Seyedsayamdost, Mohammad R;Steinberg, Peter D;Kjelleberg, Staffan;Thomas, Torsten
• 通讯作者: Thomas, Torsten