Protective roles of mitochondrial manganese-containing superoxide dismutase against various stresses in Candida albicans
Protective roles of mitochondrial manganese-containing superoxide dismutase against various stresses in Candida albicans
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作者：
Hwang, CS;Baek, YU;Kang, SO
白色念珠菌含有含铜和锌的超氧化物歧化酶，但也含有两种含锰的超氧化物歧化酶（MnSOD），一种在细胞质中，另一种在线粒体中。其中，SOD 2基因编码线粒体MnSOD的破坏和过表达，以研究其在C。白色念珠菌缺乏线粒体MnSOD的无效突变体比野生型细胞对各种应激更敏感，如氧化还原循环剂，加热，乙醇，高浓度的钠或钾和99.9%O-2。有趣的是，sod 2/sod 2突变体比野生型对锂和二酰胺的抗性更强，而SOD 2的过表达增加了C.白色念珠菌对这些化合物。当sod 2/sod 2和SOD 2过表达细胞在含有硫化合物如蛋氨酸、半胱氨酸、谷胱甘肽或亚硫酸盐的合成葡萄糖培养基上生长时，线粒体MnSOD对锂毒性的逆效应被缓解，表明线粒体MnSOD可能通过硫代谢影响锂毒性。此外，破坏或过表达的SOD 2增加或减少谷胱甘肽还原酶活性和抗氰呼吸交替氧化酶，分别。这些结果表明，线粒体MnSOD在胁迫反应、锂毒和抗氰呼吸中起重要作用。白色念珠菌。版权所有（C）2003约翰威利父子有限公司。
Candida albicans contains copper- and zinc-containing superoxide dismutase but also two manganese-containing superoxide dismutases (MnSODs), one in the cytosol and the other in the mitochondria. Among these, the SOD2 gene encoding mitochondrial MnSOD was disrupted and overexpressed to investigate its roles in C. albicans. The null mutant lacking mitochondrial MnSOD was more sensitive than wild-type cells to various stresses, such as redox-cycling agents, heating, ethanol, high concentration of sodium or potassium and 99.9% O-2. Interestingly, the sod2/sod2 mutant was rather more resistant to lithium and diamide than the wild-type, whereas overexpression of SOD2 increased susceptibility of C. albicans to these compounds. The inverse effect of mitochondrial MnSOD on lithium toxicity was relieved when the sod2/sod2 and SOD2-overexpressing cells were grown on the synthetic dextrose medium containing sulphur compounds such as methionine, cysteine, glutathione or sulphite, indicating that mitochondrial MnSOD may affect lithium toxicity through sulphur metabolism. Moreover, disruption or overexpression of SOD2 increased or decreased glutathione reductase activity and cyanide-resistant respiration by alternative oxidase, respectively. Taken together, these findings suggest that mitochondrial MnSOD is important for stress responses, lithium toxicity and cyanide-resistant respiration of C. albicans. Copyright (C) 2003 John Wiley Sons, Ltd.