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

由于植物不能移动，它们已经发展了几种机制来生存非生物胁迫，如寒冷和干旱。随着人为的全球变暖，这些压力可能会变得更加频繁和更加不可预测。我们的研究计划以了解脱水蛋白（脱水蛋白）的结构和功能为中心。遗传和蛋白质表达研究表明，甜菜碱是植物在这些非生物胁迫下生存所必需的。这些蛋白质的功能机制尚未完全阐明。部分原因在于，甜菜碱是高度亲水性的蛋白质，这使得它们本质上是无序的。正因为如此，它们不遵循蛋白质需要具有明确定义的结构并与配体具有特异性相互作用以具有生物学功能的标准范式。我们的建议的一个主要部分是使用在细胞NMR检查的结构和功能的最小（K2葡萄糖）和模型（YSK 2葡萄糖）从葡萄属riparia（野生葡萄）。这将需要使用细胞穿透肽，以获得葡萄细胞内的同位素标记蛋白质。这些结果将捕获一种内在无序蛋白质在其天然环境中的结构和行为。我们还将剖析在结合和保护DNA免受由活性氧引起的损伤，这是在寒冷和干旱形成的作用。通过确定这些保护蛋白在脱水过程中发挥作用的机制，我们将扩大对酶的保护作用的理解。我们还将利用生物信息学的力量来研究保守的蛋白质序列，一个不平凡的问题，由于减少结构约束，内在无序的蛋白质序列以更快的速度进化。与此相关，我们还将研究抗氧化蛋白的进化，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。

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.**