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。大多数作物植物对盐胁迫高度敏感，盐胁迫往往会由于渗透胁迫而引起水分亏缺，并且由于有毒的过量细胞内钠而引起若干生化问题。有些植物品种的耐盐性差别很大。钠/氢（Na+/H+）反向转运蛋白是从植物和酵母细胞内去除盐的膜蛋白。Na+/H+反向转运蛋白的过表达已显示赋予植物改善的耐盐性，允许它们在更咸的土壤中生长。我们项目的目的是了解Na+/H+反向转运蛋白的工作原理，也就是说，更好地了解它们从细胞中去除盐的方式。为此，我们使用酵母模型系统来研究Na+/H+反向转运蛋白的功能。酵母具有与植物Na+/H+反向转运蛋白非常相似的Na+/H+反向转运蛋白。它们在蛋白质序列上是相关的，可以相互替换并正常发挥功能。该项目有几个部分。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。我们使用了一种Na+/H+反向转运蛋白缺失的酵母，并在蛋白质中进行突变后将Na+/H+反向转运蛋白返回到酵母中。然后我们研究蛋白质的功能。在研究的另一部分，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，使我们可以标记的Na+/H+反向转运蛋白与特定的标签。这些使我们能够识别蛋白质上标签的位置，并为我们提供蛋白质拓扑结构（或结构）的概念。总的来说，该项目将帮助我们了解蛋白质的工作原理，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.