Assessment of Molecular Mechanisms involved in Nitrogen Cost Minimization of Oligotrophic Microorganisms

寡营养微生物氮成本最小化的分子机制评估

• 批准号: 1244630
• 负责人: Joseph Grzymski
• 金额: $ 5.07万
• 依托单位: Nevada System of Higher Education, Desert Research Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1244630&HistoricalAwards=false
• 关键词: Assessment; Molecular; Mechanisms; involved; Nitrogen

Intellectual Merit: Nitrogen cost-minimization (the reduction of nitrogen in cellular structures, especially protein) is a common and important strategy for marine microbes that thrive in oligotrophic waters. This is evidenced by the most successful organisms having low G+C genomes and thus using amino acids that have fewer N atoms in side chains and by the necessary trade-off this strategy entails - that proteins are, on average, larger in mass (require more non-limiting carbon). This project's core hypothesis is that cost-minimized organisms have specific genomic and molecular adaptations that promote nitrogen thrift and maintain a slow and steady approach to growth. Specifically, these organisms have sacrificed potential efficiencies in translation and regulation to maintain growth under any condition. They grow slowly regardless of substrate availability - there are fundamental limitations in metabolic and cell processes. It is posited that slow and steady growth hard-wired into the genetic code alleviates the need for more complex transcriptional regulation and complex, protein intensive redox sensing pathways. The experimental plan will test this core hypothesis by quantifying the primary transcriptome and local translation rates of a strain of Prochlorococcus grown under high and low nitrogen conditions.Broader Impacts: Transcription and translation are fundamental cellular processes that help set maximum growth rates of an organism. New techniques will be applied to capture a detailed picture of the transcriptional landscape of Prochlorococcus, and this has the potential to yield transformative information on the relationships between cost minimization and transcriptional complexity for one of the most abundant microbes on earth. The data generated during this project will be a rich resource to researchers in many fields; all of the data generated during this project will be released to public databases. This project has graduate and middle school educational components. The extensive laboratory and computer work offers a diverse educational potential using cutting-edge laboratory and bioinformatic techniques. Public outreach will involve a continued effort by the PI and his lab to engage, promote and improve science education in Nevada's poorest schools. This work will also contribute to the further development of the NSF-EPSCoR infrastructure and research activities in Nevada.

智力优点：氮成本最小化（减少细胞结构中的氮，特别是蛋白质）是在贫营养水域中繁衍生息的海洋微生物的常见且重要的策略。最成功的生物体具有低 G+C 基因组，因此使用侧链中 N 原子较少的氨基酸，并且该策略需要进行必要的权衡，这证明了这一点 - 蛋白质的平均质量更大（需要更多的非限制性碳）。该项目的核心假设是，成本最小化的生物体具有特定的基因组和分子适应性，可以促进氮节约并保持缓慢而稳定的生长方式。具体来说，这些生物体牺牲了翻译和调节的潜在效率，以在任何条件下维持生长。无论底物可用性如何，它们都生长缓慢 - 代谢和细胞过程存在根本限制。据推测，缓慢而稳定的生长硬连接到遗传密码中，减轻了对更复杂的转录调控和复杂的蛋白质密集型氧化还原传感途径的需求。该实验计划将通过量化在高氮和低氮条件下生长的原绿球藻菌株的主要转录组和局部翻译率来测试这一核心假设。更广泛的影响：转录和翻译是帮助设定生物体最大生长速率的基本细胞过程。新技术将用于捕获原绿球菌转录景观的详细图片，这有可能产生关于地球上最丰富的微生物之一的成本最小化和转录复杂性之间关系的变革性信息。该项目产生的数据将成为许多领域研究人员的丰富资源；该项目期间产生的所有数据都将发布到公共数据库。该项目包含研究生和中学教育部分。广泛的实验室和计算机工作利用尖端的实验室和生物信息技术提供了多样化的教育潜力。公共宣传活动将涉及 PI 及其实验室的持续努力，以参与、促进和改善内华达州最贫困学校的科学教育。这项工作还将有助于内华达州 NSF-EPSCoR 基础设施和研究活动的进一步发展。