Ruiz-Castilla Francisco J, Rodríguez-Castro Elisa, Michán Carmen, Ramos José
Department of Agricultural Chemistry, Edaphology and Microbiology, University of Córdoba, E-14071 Córdoba, Spain.
Department of Biochemistry and Molecular Biology, Campus de Excelencia Internacional Agroalimentario CeiA3, University of Córdoba, 14071 Córdoba, Spain.
J Fungi (Basel). 2021 May 6;7(5):362. doi: 10.3390/jof7050362.
The three families of yeast plasma membrane potassium influx transporters are represented in : Trk, Acu, and Hak proteins. Hak transporters work as K-H symporters, and the genes coding for Hak proteins are transcriptionally activated under potassium limitation. This work shows that mutant cells lacking display a severe growth impairment at limiting potassium concentrations under acidic conditions. This is the consequence of a defective capacity to transport K, as indicated by potassium absorption experiments and by the kinetics parameters of Rb (K) transport. Moreover, cells are more sensitive to the toxic cation lithium. All these phenotypes became much less robust or even disappeared at alkaline growth conditions. Finally, transcriptional studies demonstrate that the mutant, in comparison with cells, activates the expression of the K/Na ATPase coded by in the presence of Na or in the absence of K.
酵母质膜钾离子流入转运蛋白的三个家族分别由Trk、Acu和Hak蛋白代表。Hak转运蛋白作为钾-氢同向转运体发挥作用，编码Hak蛋白的基因在钾限制条件下会被转录激活。这项研究表明，缺乏[具体蛋白名称未给出]的突变细胞在酸性条件下的低钾浓度环境中表现出严重的生长缺陷。钾吸收实验以及铷（钾）转运的动力学参数表明，这是钾转运能力缺陷的结果。此外，[具体细胞名称未给出]细胞对有毒阳离子锂更敏感。在碱性生长条件下，所有这些表型都变得不那么明显甚至消失。最后，转录研究表明，与[具体细胞名称未给出]细胞相比，[具体突变细胞名称未给出]突变体在有钠存在或无钾存在的情况下会激活由[具体基因名称未给出]编码的钾/钠ATP酶的表达。
