Molecular analysis of salt tolerance proteins

土壤盐分是降低植物生长和生产力的主要因素。大多数农作物对盐胁迫高度敏感，盐胁迫往往会导致渗透胁迫导致水分亏缺，而渗透胁迫又会由于有毒的细胞内过量钠而导致一些生化问题。有些植物的耐盐性差异很大。钠/氢(Na/H)逆向转运蛋白是一种膜蛋白，可以从植物和酵母的细胞内清除盐分。Na/H逆向转运蛋白的过度表达已被证明可以提高植物的耐盐性，使它们能够在盐分较高的土壤中生长。我们项目的目的是了解Na/H逆向转运蛋白是如何工作的，也就是更好地了解它们是如何将盐从细胞中清除出去的。为了做到这一点，我们正在使用酵母的模型系统来研究Na/H逆向转运蛋白如何发挥作用。酵母的Na/H逆向转运蛋白与植物的Na/H逆向转运蛋白非常相似。它们在蛋白质序列上是相关的，可以相互替代，发挥正常的功能。该项目包括几个部分。在一个部分中，我们正在学习蛋白质的哪些区域在活动中是重要的。我们使用一种缺失了Na/H反向转运蛋白的酵母，在我们对蛋白质进行突变后，将Na/H反向转运蛋白重新注入酵母。然后我们研究蛋白质是如何发挥作用的。在这项研究的另一部分中，我们正在生产蛋白质，并将使用核磁共振和电子显微镜检查蛋白质结构。这将给我们一张蛋白质的图片。此外，我们将使用一种技术，通过这种技术，我们可以用特定的标签标记Na/H逆向转运蛋白。这使我们能够识别蛋白质上标签的位置，并让我们对蛋白质的拓扑(或结构)有一个了解。总体而言，该项目将帮助我们了解这种蛋白质的工作原理，使我们能够更好地设计可用于提高植物耐盐性的蛋白质。

Soil salinity is a major factor in reducing plant growth and productivity. Most crop plants are highly sensitive to salt stress that tends to cause a water deficit due to osmotic stress, and that causes several biochemical problems due to toxic excess intracellular sodium. The degree of salt tolerance of some plant species varies greatly. Sodium/Hydrogen (Na+/H+) antiporters are membrane proteins that remove salt from inside the cells of plants and yeast. Overexpression of Na+/H+ antiporters has been shown to confer improved salt tolerance in plants allowing them to grow in saltier soils. The purpose of our project is to understand how Na+/H+ antiporters work, that is, to better understand the way that they remove salt out of cells. To do this we are using a model system of yeast to study how Na+/H+ antiporters function. Yeast have Na+/H+ antiporters that are very similar to plant Na+/H+ antiporters. They are related in protein sequence and can replace each other and function normally. There are several parts to the project. In one part we are learning which regions of the protein are important in activity. We use a yeast that has its Na+/H+ antiporter deleted and return the Na+/H+ antiporter into the yeast after we make mutations in the protein. Then we study how the protein functions. In another part of the study we are producing the protein and will examine the protein structure using nuclear magnetic resonance and electron microscopy. This will give us a picture of the protein. Additionally, we will use a technique whereby we can label the Na+/H+ antiporter protein with specific tags. These allow us to identify the location of the tags on the protein and give us an idea of the topology (or structure) of the protein. Overall, the project will help us understand how the protein works, allowing us to better design proteins that can be used to improve salt tolerance in plants.