Why do bacteria make sterols?

[中文摘要]，为什么细菌需要甾醇？第一部分非技术：这个项目研究细胞生物学中的一个基本问题：为什么细菌会产生固醇？甾醇是一种脂质（脂肪）分子，在真核生物（人类、动物和植物）细胞中具有多种生物学作用。这些作用包括维持细胞膜的结构和功能。最有名的固醇可能是胆固醇。一些细菌也产生甾醇，但其作用尚不清楚，因为据报道细菌细胞膜不需要甾醇。发现细菌甾醇的作用将是一个重大的贡献，因为对甾醇功能的认识将得到扩展。这与社会有着更广泛的相关性，因为甾醇作为细胞组成部分的基本重要性，而且在更实际的方面也是如此。例如，胆固醇等甾醇在人体生理中是必不可少的，真菌甾醇的合成可以通过特定药物靶向治疗真菌感染。该项目还将通过提供现代生物和分析化学技术的尖端培训来增强该国的科学劳动力。第二部分技术：该项目的目标是确定甾醇在隐盲芽胞菌中的作用，这是第一种甾醇已被证明是必不可少的细菌。G. obscuriglobus具有独特的真核样、甾醇相关的细胞特征，包括出芽复制、复杂的胞膜和内吞样行为。核心假设是，与真核生物的甾醇相比，Gemmata甾醇具有更广泛的功能库，包括真核生物中已知的甾醇功能，以及细菌细胞环境中特有的新功能。提出这项研究的基本原理是，它将扩大我们对甾醇的功能和进化的理解，并揭示真核和原核甾醇的作用重叠。项目目标将通过追求以下具体目标来实现：(1)确定隐球菌甾醇如何支持芽殖复制；(2)确定隐红弧菌甾醇对内吞样活性的贡献；(3)确定甾醇类对隐木斑鱼磷脂代谢的影响。研究方法包括显微镜、蛋白质组学和脂质组学。该项目的预期结果是提高对甾醇功能的理解，以及甾醇对真核生物细菌膜介导过程的潜在贡献，以及细菌特有的新功能。这将具有重要的积极影响，因为它将潜在地揭示以前未被发现的原核和真核细胞结构和功能的相似性和差异性。更广泛的影响包括微生物学，这是一个独特的科学艺术教育和推广项目，其中微生物及其细胞结构作为主题。将产生多种教育和推广产品，包括K-12参与，微生物学将被纳入人文和科学的本科教学。参与该项目将为研究生和本科生提供细胞生物学和分析化学的跨学科培训，他们也将成为创建和传播微生物学的关键人员。

AbstractNaomi Ward, 1656637, Why do bacteria need sterols?Part I Non-technical: This project pursues a fundamental question in cell biology: why do bacteria make sterols? Sterols are lipid (fat) molecules that have multiple biological roles in eukaryotic (human, animal, and plant) cells. These roles include maintaining the structure and function of cell membranes. The best-known sterol is probably cholesterol. Sterols are also produced by some bacteria, but their purpose is unknown because bacterial cell membranes are not reported to need sterols. Discovering the purpose of bacterial sterols will make a significant contribution because knowledge of sterol function, in general, will be expanded. This is of broader relevance to society because of the fundamental importance of sterols as cellular building blocks, but also in more practical terms. For example, sterols such as cholesterol are essential in human physiology, and fungal sterol synthesis can be targeted by specific drugs to treat fungal infections. The project will also enhance the country's scientific workforce by providing cutting edge training in modern biological and analytical chemistry technologies. Part II Technical: The project goal is to determine the role of sterols in Gemmata obscuriglobus, the first bacterium in which sterols have been shown to be essential. G. obscuriglobus possesses a unique constellation of eukaryote-like, sterol-associated, cellular features, including budding replication, complex intracellular membranes, and endocytosis-like behavior. The central hypothesis is that that Gemmata sterols have an expanded functional repertoire relative to eukaryotic sterols, including known functions of sterols in eukaryotes, as well as novel functions specific to a bacterial cellular context. The rationale for the proposed research is that it will expand our functional and evolutionary understanding of sterols, and uncover overlaps in the roles of eukaryotic and prokaryotic sterols. The project objective will be achieved by pursuing the following Specific Aims: (1) Determine how G. obscuriglobus sterols support budding replication; (2) Identify the contribution of G. obscuriglobus sterols to endocytosis-like activity; (3) Establish the effect of sterols on phospholipid metabolism in G. obscuriglobus. Research methods include microscopy, proteomics, and lipidomics. The expected outcome of the project is an improved understanding of sterol function, and the potential contribution of sterols to bacterial membrane-mediated processes characteristic of eukaryotes, as well as novel functions specific to bacteria. This will have important positive impact because it will potentially reveal previously undetected similarities and differences in prokaryotic and eukaryotic cell structures and functions. Broader Impacts include the Microbestiary, a unique science-art education and outreach project, where microbes and their cell structures serve as the subject matter. Multiple education and outreach products, including K-12 participation, will be generated, and the Microbestiary will be incorporated into undergraduate teaching in the humanities and sciences. Participation in this project will provide interdisciplinary training in cell biology and analytical chemistry for graduate and undergraduate students, who will also be key personnel for creating and disseminating the Microbestiary.