Pathogenic Candida species differ in the ability to grow at limiting potassium concentrations
Pathogenic Candida species differ in the ability to grow at limiting potassium concentrations
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DOI：
10.1139/cjm-2015-0766
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发表时间：
2016-05-01
影响因子：
2.8
通讯作者：
Sychrova, H.
中科院分区：
文献类型：
--
作者：
Husekova, B.;Elicharova, H.;Sychrova, H.
高细胞内钾浓度（200-300 mmol/L）对酵母细胞的许多功能至关重要，如调节细胞体积和pH值，维持膜电位和酶活化。因此，细胞使用高亲和力的特异性转运体，并消耗大量能量从环境中获取所需的钾。在念珠菌基因组中，鉴定出编码3种可能的钾摄取系统的基因：Trk单转运蛋白、Hak同转运蛋白和Acu atp酶。白念珠菌、dubliniensis、C. glabrata、C. krusei、C. parapsilosis和C. tropicalis对不同钾浓度的耐受性和敏感性试验表明，不同物种之间存在显著差异，这些差异部分取决于外部ph。对钾限制条件最耐受的物种是白色念珠菌和C. krusei，而C. parapsilosis对KCl浓度的耐受性最高。细胞形态也随钾含量的变化而变化，其中对克鲁塞草和热带草影响最大。综上所述，我们的研究结果证实了钾的摄取和积累是念珠菌细胞生长的重要因素，并表明krusei和C. glabrata唯一的（因此可能是必不可少的）Trk1钾摄取系统可能作为开发新的抗真菌药物的靶点。
A high intracellular concentration of potassium (200-300 mmol/L) is essential for many yeast cell functions, such as the regulation of cell volume and pH, maintenance of membrane potential, and enzyme activation. Thus, cells use high-affinity specific transporters and expend a lot of energy to acquire the necessary amount of potassium from their environment. In Candida genomes, genes encoding 3 types of putative potassium uptake systems were identified: Trk uniporters, Hak symporters, and Acu ATPases. Tests of the tolerance and sensitivity of C. albicans, C. dubliniensis, C. glabrata, C. krusei, C. parapsilosis, and C. tropicalis to various concentrations of potassium showed significant differences among the species, and these differences were partly dependent on external pH. The species most tolerant to potassium-limiting conditions were C. albicans and C. krusei, while C. parapsilosis tolerated the highest KCl concentrations. Also, the morphology of cells changed with the amount of potassium available, with C. krusei and C. tropicalis being the most influenced. Taken together, our results confirm potassium uptake and accumulation as important factors for Candida cell growth and suggest that the sole (and thus probably indispensable) Trk1 potassium uptake system in C. krusei and C. glabrata may serve as a target for the development of new antifungal drugs.