Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China.
The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
Mycopathologia. 2018 Apr;183(2):315-327. doi: 10.1007/s11046-017-0216-7. Epub 2017 Oct 30.
The vacuolar-type H-ATPase (V-ATPase) is essential for many cell processes. Our previous study has demonstrated that Tfp1 is a putative subunit of V-ATPase, loss of which causes disorders in calcium homeostasis and decreased resistance to oxidative stress. In this study, we found that further deletion of PMC1, a vacuolar calcium pump, in tfp1∆/∆ mutant led to more severe dysregulation of calcium homeostasis. Besides, the tfp1∆/∆pmc1∆/∆ mutant was more sensitive to HO and had a higher ROS level. As is known, V-ATPase mutants are sensitive to NaCl, and PMC1 mutant is resistant against NaCl. However, the tfp1∆/∆pmc1∆/∆ mutant exhibited sensitivity to NaCl. Mechanism study demonstrated that their sensitivity was associated with reduced osmotic resistance caused by relatively low expression of GPD1. In addition, we first found that NaCl addition significantly declined ROS levels in tfp1∆/∆ and tfp1∆/∆pmc1∆/∆ mutants. In tfp1∆/∆ mutant, decreased ROS levels were relevant to enhanced antioxidant activities. However, in tfp1∆/∆pmc1∆/∆ mutant, reduced ROS resulted from decreased total calcium content, revealing that NaCl affected ROS levels in the two mutants through different mechanisms. Taken together, our data indicated that loss of both TFP1 and PMC1 further affected calcium homeostasis and other cellular processes in Candida albicans and provides a potential antifungal target.
液泡型 H+-ATP 酶（V-ATPase）对于许多细胞过程是必不可少的。我们之前的研究表明，Tfp1 是 V-ATPase 的一个假定亚基，其缺失会导致钙稳态紊乱和氧化应激抗性降低。在这项研究中，我们发现进一步缺失 vacuolar calcium pump PMC1 会导致 tfp1∆/∆ 突变体中钙稳态的严重失调。此外，tfp1∆/∆pmc1∆/∆ 突变体对 HO 更敏感，ROS 水平更高。众所周知，V-ATPase 突变体对 NaCl 敏感，而 PMC1 突变体对 NaCl 有抗性。然而，tfp1∆/∆pmc1∆/∆ 突变体对 NaCl 表现出敏感性。机制研究表明，它们的敏感性与 GPD1 相对低表达导致的渗透抗性降低有关。此外，我们首次发现 NaCl 添加显著降低了 tfp1∆/∆ 和 tfp1∆/∆pmc1∆/∆ 突变体中的 ROS 水平。在 tfp1∆/∆ 突变体中，降低的 ROS 水平与增强的抗氧化活性有关。然而，在 tfp1∆/∆pmc1∆/∆ 突变体中，ROS 的减少是由于总钙含量减少所致，这表明 NaCl 通过不同的机制影响了这两个突变体中的 ROS 水平。总之，我们的数据表明，TFP1 和 PMC1 的缺失进一步影响了白色念珠菌的钙稳态和其他细胞过程，并为潜在的抗真菌靶点提供了依据。
