Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
Int J Mol Sci. 2019 Apr 30;20(9):2133. doi: 10.3390/ijms20092133.
Sodium and potassium are two alkali cations abundant in the biosphere. Potassium is essential for plants and its concentration must be maintained at approximately 150 mM in the plant cell cytoplasm including under circumstances where its concentration is much lower in soil. On the other hand, sodium must be extruded from the plant or accumulated either in the vacuole or in specific plant structures. Maintaining a high intracellular K/Na ratio under adverse environmental conditions or in the presence of salt is essential to maintain cellular homeostasis and to avoid toxicity. The baker's yeast, , has been used to identify and characterize participants in potassium and sodium homeostasis in plants for many years. Its utility resides in the fact that the electric gradient across the membrane and the vacuoles is similar to plants. Most plant proteins can be expressed in yeast and are functional in this unicellular model system, which allows for productive structure-function studies for ion transporting proteins. Moreover, yeast can also be used as a high-throughput platform for the identification of genes that confer stress tolerance and for the study of protein-protein interactions. In this review, we summarize advances regarding potassium and sodium transport that have been discovered using the yeast model system, the state-of-the-art of the available techniques and the future directions and opportunities in this field.
钠和钾是生物圈中两种丰富的碱金属阳离子。钾对植物是必需的，其浓度必须在植物细胞质中维持在约 150mM 左右，包括在土壤中浓度低得多的情况下。另一方面，钠必须从植物中排出，或者在液泡或特定的植物结构中积累。在不利的环境条件下或存在盐的情况下，维持高细胞内 K/Na 比对于维持细胞内稳态和避免毒性是至关重要的。面包酵母 多年来一直被用于鉴定和表征植物中钾和钠稳态的参与者。其用途在于膜和液泡之间的电梯度与植物相似。大多数植物蛋白可以在酵母中表达，并且在这个单细胞模型系统中具有功能，这允许对离子转运蛋白进行富有成效的结构-功能研究。此外，酵母还可以用作鉴定赋予抗逆性的基因和研究蛋白质-蛋白质相互作用的高通量平台。在这篇综述中，我们总结了使用酵母模型系统发现的钾和钠转运方面的进展，介绍了现有技术的最新水平，以及该领域的未来方向和机遇。
