The Regulation of Protein Synthesis by Oxygen

氧对蛋白质合成的调节

• 批准号: RGPIN-2022-03458
• 负责人: Uniacke, Jim
• 金额: $ 3.5万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=761167
• 关键词: Regulation; Protein; Synthesis; Oxygen

One of the criteria for life is the ability of an organism to respond to stimuli and adapt. My research program focuses on this criterion with regard to the protein synthesis machinery. Also known as translation, protein synthesis is a fundamental biological process in the flow of genetic information from messenger ribonucleic acid (mRNA) into protein. Cellular stress leads to a refocusing of translation efforts away from the maintenance of basic cell functions and toward the production of stress response proteins. This occurs by repressing canonical cap-dependent translation initiation, which accesses mRNAs through their 5' cap and accounts for >95% of translation. My research program addresses a major question in cell biology: how do cells translate their mRNAs into protein during periods of stress when cap-dependent translation is repressed? We focus on hypoxia (low oxygen) in human cells because adequate oxygen acquisition has been one of life's most essential adaptive processes to maximize cellular energy production. Indeed, the 2019 Nobel Prize in Physiology or Medicine was awarded to Drs. Kaelin, Ratcliffe, and Semenza for their discoveries of how cells sense and adapt to oxygen availability. Until relatively recently, it was thought that hypoxic cells switch from canonical cap-dependent translation (mediated by the cap-binding eIF4E) to cap-independent processes to translate select mRNAs during stress. Our lab studies a non-canonical cap-dependent translation pathway, discovered during my postdoctoral research, that is required for human cells to adapt to hypoxia. This pathway utilizes the cap-binding protein eIF4E2, but many questions remain. The Aims in this proposal seek to discover how low oxygen availability generates a specialized translation response through the recruitment of specialized translation factors (Aim 1) and ribosomes (Aim 2). We will also investigate how gene expression is influenced by physiological oxygen, which is the environment where human cells reside (Aim 3). We will monitor changes in the incorporation of oxidized nucleotides within DNA and RNA through immunoprecipitation and RNA sequencing. The long-term overarching goal of our research program is to highlight the plasticity of the translation apparatus that allows human cells to respond to changes in oxygen availability. My innovative research program will continue to have impacts on the natural sciences by influencing mammalian cell culture practices to include oxygen as a variable, and update current textbook models of translational control. This program will provide 3 PhD, 2 MSc, and 15 undergraduates with the opportunity to engage in cutting-edge science, with an emphasis on problem solving and collaboration. Combined with guidance and encouragement, these opportunities will lead to high impact publications and the development of imaginative, independent scientists who will be well prepared for careers in Canadian academia, government, and industry.

生命的标准之一是有机体对刺激做出反应和适应的能力。我的研究计划重点介绍了有关蛋白质合成机械的标准。蛋白质合成也称为翻译，是从信使核糖核酸（mRNA）流向蛋白质的基本生物学过程。细胞应激导致翻译工作的重新聚焦，从基本细胞功能的维持和应力反应蛋白的产生。这是通过抑制规范帽依赖性的翻译启动来发生的，该启动通过其5'上限访问mRNA，占翻译的95％> 95％。我的研究计划解决了细胞生物学的一个主要问题：在压抑帽依赖性翻译时，细胞如何将其mRNA转化为蛋白质？我们专注于人类细胞中的缺氧（低氧），因为足够的氧气获取一直是生命中最大程度地提高细胞能量产生的最重要的自适应过程之一。确实，2019年诺贝尔生理学或医学奖已授予博士。 Kaelin，Ratcliffe和Semenza发现细胞如何感知和适应氧气可用性。直到最近，人们认为低氧细胞从规范帽依赖性翻译（由帽结合EIF4E介导）转换为盖无依赖性过程，以在应力期间翻译精选的mRNA。我们的实验室研究在我的博士后研究中发现的一种非规范帽依赖性翻译途径是人类细胞适应缺氧所必需的。该途径利用了结合蛋白EIF4E2，但仍然存在许多问题。该提案中的目的旨在通过募集专业翻译因子（AIM 1）和核糖体（AIM 2）来发现低氧的可用性如何产生专业翻译响应。我们还将研究基因表达如何受到人类细胞居住的环境的生理氧影响（AIM 3）。我们将通过免疫沉淀和RNA测序来监测DNA和RNA中氧化核苷酸掺入的变化。我们的研究计划的长期总体目标是突出翻译设备的可塑性，该设备使人类细胞能够对氧气可用性的变化做出反应。我的创新研究计划将通过影响哺乳动物细胞培养实践将氧气作为变量，并更新当前的翻译控制教科书模型，从而继续对自然科学产生影响。 该计划将提供3个博士学位，2个MSC和15位大学生，并有机会从事尖端科学，重点是解决问题和协作。结合指导和鼓励，这些机会将导致高影响力的出版物以及富有想象力的独立科学家的发展，这些科学家将为加拿大学术界，政府和工业的职业做好充分的准备。