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）：微生物之间的共生相互作用在自然界中是丰富的。研究这些相互作用所需的遗传、生化和化学技术的不同寻常的组合阻碍了它们的详细分析，因此大多数仍然没有得到很好的检验。最丰富和对环境最重要的共生现象之一发生在海洋中，发生在微小的藻类之间，比如赫胥黎埃米利亚藻，和玫瑰杆菌分支的细菌，比如gallaecphaeobacter。E. huxleyi占据了所有阳光照射的海洋层，在全球氧和碳循环中起着重要作用。它形成大量的季节性开花，在那里它间歇性地与玫瑰杆菌分支的成员联系在一起。玫瑰杆菌在沿海地区普遍存在，在全球硫循环中起着重要作用。虽然玫瑰杆菌-藻类共生驱动了许多生物地球化学过程，但这些相互作用的分子原理仍然未知。我们的初步结果表明，P. gallaeciensis，根据不同的情况，产生一种有效的，新的代谢物，杀死E. huxleyi。提出的研究计划旨在1)发现介导或调节玫瑰杆菌与藻类相互作用的全球调节因子和小分子信号；2)使用基于核磁共振的方法表征玫瑰杆菌响应藻类信号产生的次级代谢物的结构，并使用生物测定法确定其功能；3)通过转座子诱变、基因缺失和酶促研究描绘这些代谢物的生物合成途径。4)揭示代谢产物的产生是如何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，以检查赫胥黎E.和P. gallaeciensis发现的原理的普遍性。这项研究计划将产生表征许多类似的环境重要相互作用所需的工具。由于共生体中含有一种尚未开发的代谢物储存库，具有潜在的制药和/或农业应用价值，因此该提议也可以识别出新的有用分子。哈佛医学院在这一领域或工作中提供了一个知识利基和一个成熟的研究项目。它由天然产物化学和细菌遗传学领域的领导者组成，他们将作为我拟议项目的导师。在获得机械酶学博士学位后，我的短期目标是获得必要的技能来研究微生物共生的各个方面。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，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生产的调节和检查生物合成酶。从长远来看，我计划在学术机构领导一个多学科研究项目，研究环境重要共生体的基础化学、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.

• DOI: 10.1128/mbio.02118-15
• 发表时间: 2016-03-22
• 期刊: mBio
• 影响因子: 6.4
• 作者: Wang R;Gallant É;Seyedsayamdost MR
• 通讯作者: Seyedsayamdost MR

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

• DOI: 10.1371/journal.pone.0027387
• 发表时间: 2011
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Fernandes N;Case RJ;Longford SR;Seyedsayamdost MR;Steinberg PD;Kjelleberg S;Thomas T
• 通讯作者: Thomas T

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。

• DOI: 10.1042/ebc20160072
• 发表时间: 2017
• 期刊: Essays in biochemistry
• 影响因子: 6.4
• 作者: Reece,StevenY;Seyedsayamdost,MohammadR
• 通讯作者: Seyedsayamdost,MohammadR