The in cell structure and function of an intrinsically disordered plant stress protein

本质无序植物应激蛋白的细胞内结构和功能

• 批准号: RGPIN-2016-04253
• 负责人: Graether, Steffen
• 金额: $ 3.21万
• 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=761148
• 关键词: cell; structure; function; intrinsically; disordered

Because plants are unable to move, they have developed several mechanisms to survive abiotic stresses such as cold and drought. With anthropogenic global warming these stresses are likely to become more frequent and more unpredictable. Our research proposal centers on understanding the structure and function of dehydrins (dehydration proteins). Genetic and protein expression studies have shown that dehydrins are essential for plants to survive these abiotic stresses. The mechanisms by which these proteins function has not yet been fully elucidated. Part of the issue is that dehydrins are highly hydrophilic proteins, which makes them intrinsically disordered. Because of this, they do not follow the standard paradigm that a protein needs to have a well-defined structure and have specific interactions with a ligand in order to have a biological function. A major part of our proposal is to use in cell NMR to examine the structure and function of a minimal (K2 dehydrin) and model (YSK2 dehydrin) from Vitis riparia (wild grape). This will require the use of cell-penetrating peptides in order to get the isotopically labelled protein inside the grape cell. The results will capture the structure and behaviour of an intrinsically disordered protein in its native environment. We will also dissect dehydrin's role in the binding and protection of DNA from damage caused by reactive oxygen species, which are formed during cold and drought. Our understanding of the protective roles of dehydrins on enzymes will be expanded by determining the mechanism by which these protective proteins function during dehydration. We will also use the power of bioinformatics to examine the conservation of dehydrin sequences, a non-trivial problem given that intrinsically disordered protein sequences evolve at a much faster rate due to reduced structural constrains. Related to this, we will also examine the evolution of dehydrins and test our hypothesis that they evolved as a frameshift mutation of an ordered stress-response protein.

由于植物无法移动，它们形成了多种机制来抵御寒冷和干旱等非生物胁迫。随着人为全球变暖，这些压力可能会变得更加频繁和更加不可预测。我们的研究计划集中于了解脱水蛋白（脱水蛋白）的结构和功能。遗传和蛋白质表达研究表明，脱水蛋白对于植物在这些非生物胁迫下生存至关重要。这些蛋白质发挥作用的机制尚未完全阐明。部分问题在于脱水蛋白是高度亲水性蛋白质，这使得它们本质上是无序的。因此，它们不遵循标准范例，即蛋白质需要具有明确的结构并与配体具有特定的相互作用才能具有生物学功能。我们建议的一个主要部分是使用细胞核磁共振来检查来自葡萄（野生葡萄）的最小（K2 脱水蛋白）和模型（YSK2 脱水蛋白）的结构和功能。这需要使用细胞穿透肽，以便在葡萄细胞内获得同位素标记的蛋白质。结果将捕获本质上无序的蛋白质在其天然环境中的结构和行为。我们还将剖析脱水素在结合和保护 DNA 免受活性氧（活性氧在寒冷和干旱期间形成）造成的损伤方面的作用。通过确定这些保护蛋白在脱水过程中发挥作用的机制，我们将进一步了解脱水蛋白对酶的保护作用。我们还将利用生物信息学的力量来检查脱水蛋白序列的保守性，这是一个不小的问题，因为本质上无序的蛋白质序列由于结构限制的减少而以更快的速度进化。与此相关，我们还将研究脱水蛋白的进化，并检验我们的假设，即它们是作为有序应激反应蛋白的移码突变而进化的。