Elucidating the biogenesis of peroxisomes in plants: Formation of peroxisomes at the ER and membrane protein trafficking, and peroxisome-organelle interactions

阐明植物中过氧化物酶体的生物发生：内质网过氧化物酶体的形成和膜蛋白运输，以及过氧化物酶体-细胞器相互作用

• 批准号: RGPIN-2018-04629
• 负责人: Mullen, Robert
• 金额: $ 3.42万
• 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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=689466
• 关键词: Elucidating; biogenesis; peroxisomes; plants; Formation

A hallmark of eukaryotic cells is the compartmentalization or "division of labor" of distinct metabolic pathways into separate subcellular organelles, a process that is mediated by the proper intracellular trafficking of each organelle's protein constituents. Research described in this proposal is a continuum of our overarching goal of understanding the biology of plant peroxisomes - organelles that participate in a vast array of metabolic and physiological functions in plants. Indeed, recent studies have revealed new and unexpected roles for plant peroxisomes, indicating that this organelle is a key target for future bioengineering or molecular breeding strategies aimed at modifying plant metabolism, energy-dense biomass production, stress tolerance and pathogen defense responses. *** Plant peroxisomes are remarkably dynamic in terms of their biogenesis, i.e., how they are initially formed and maintained in the cell, how they interact with other organelles, and ultimately how they are turned over. The emphasis of the proposed research is aimed at elucidating the complex molecular mechanisms that underlie these processes. Specifically, our objectives are to decipher the role of the endoplasmic reticulum (ER) in the formation of new peroxisomes and/or the maintenance of pre-existing peroxisomes, and how this process compares to the formation of new organelles by peroxisomal fission. We also plan to elucidate the specific region(s) of the ER at which peroxisomes are thought to originate, as well as the molecular targeting signals that direct membrane proteins to peroxisomes via different pathways, and to potentially different subpopulations of peroxisomes. Other proposed research involves characterization of the physical associations between peroxisomes and the ER, as well as with lipid droplets, which are subcellular organelles that store lipids in plant cells. These interactions ensure the metabolic cooperation and communication between peroxisomes and other organelles and appear to be mediated by distinct proteins that serve as membrane tethers'. *** Overall, the proposed research will utilize multidisciplinary, but complementary molecular, biochemical and cell biology-based approaches to discover new and important principals of peroxisome biology in plants and, in doing so, provide basic knowledge that will be instrumental for the future design of crops that produce important nutritional and industrial bioproducts. This research will also provide trainees with opportunities to engage in cutting-edge scientific endeavours, with an explicit emphasis on problem solving and collaboration building. These activities, combined with guidance and encouragement, will continue to lead to high-impact publications and the development of imaginative, independent young scientists who will be well prepared for careers in academia, government and/or industry.

真核细胞的一个特点是将不同的代谢途径划分为不同的亚细胞细胞器，这一过程是由每个细胞器的蛋白质成分在细胞内的适当运输所调节的。这项提案中描述的研究是我们了解植物过氧体生物学的总体目标的连续体--参与植物中大量代谢和生理功能的细胞器。事实上，最近的研究揭示了植物过氧化体的新的和意想不到的作用，表明这种细胞器是未来生物工程或分子育种策略的关键目标，旨在改变植物的新陈代谢、能源密集型生物质生产、逆境耐受性和病原体防御反应。*植物过氧化物体在其生物发生方面具有显著的动态，即它们最初是如何在细胞中形成和维持的，它们如何与其他细胞器相互作用，以及最终它们是如何被翻转的。拟议研究的重点是阐明这些过程背后的复杂分子机制。具体地说，我们的目标是破译内质网(ER)在形成新的过氧体和/或维持先前存在的过氧体中的作用，以及这一过程与通过过氧体分裂形成新细胞器的比较。我们还计划阐明内质网中被认为是过氧化体起源的特定区域(S)，以及将膜蛋白定向到不同途径的过氧体的分子靶向信号，以及潜在的不同的过氧体亚群。其他拟议的研究涉及表征过氧化体和内质网之间的物理联系，以及与脂滴之间的物理联系，脂滴是植物细胞中储存脂类的亚细胞细胞器。这些相互作用确保了过氧化物体和其他细胞器之间的代谢合作和交流，并且似乎是由充当膜纽带的不同蛋白质介导的。*总体而言，拟议的研究将利用多学科、但互补的分子、生化和细胞生物学方法来发现植物中过氧化物体生物学的新的重要原理，并通过这样做，提供将有助于未来设计生产重要营养和工业生物制品的作物的基本知识。这项研究还将为学员提供从事尖端科学工作的机会，明确强调解决问题和建立合作。这些活动，加上指导和鼓励，将继续产生影响大的出版物和培养富有想象力、独立的年轻科学家，他们将为在学术界、政府和/或工业界的职业生涯做好充分准备。