Expression of the Laccase Gene from a White Rot Fungus in Pichia pastoris Can Enhance the Resistance of This Yeast to H2O2-Mediated Oxidative Stress by Stimulating the Glutathione-Based Antioxidative System
Expression of the Laccase Gene from a White Rot Fungus in Pichia pastoris Can Enhance the Resistance of This Yeast to H2O2-Mediated Oxidative Stress by Stimulating the Glutathione-Based Antioxidative System
复制标题
白腐真菌漆酶基因在毕赤酵母中的表达可以通过刺激谷胱甘肽抗氧化系统来增强酵母对 H2O2 介导的氧化应激的抵抗力
DOI：
10.1128/aem.00218-12
复制
发表时间：
2012-08-01
影响因子：
4.4
通讯作者：
Zhang, Xiaoyu
中科院分区：
文献类型：
--
作者：
Yang, Yang;Fan, Fangfang;Zhang, Xiaoyu
漆酶是一种含铜多酚氧化酶，在工业和生物技术方面具有很大的应用潜力。先前的研究表明，真菌漆酶可能参与抵抗氧化应激，但几乎没有直接证据支持这一假设，漆酶保护细胞免受氧化应激的机制也尚不清楚。本文报道了白腐菌漆酶基因在毕赤酵母中的表达可以显著增强酵母对h2o2介导的氧化应激的抗性。漆酶在酵母中的表达被发现具有很强的清除细胞内H2O2和保护细胞免受脂质氧化损伤的能力。漆酶基因表达增加抗氧化应激能力的机制进一步研究。我们发现毕赤酵母中漆酶基因的表达可以提高基于谷胱甘肽的抗氧化活性水平，包括细胞内谷胱甘肽水平以及谷胱甘肽过氧化物酶、谷胱甘肽还原酶和γ -谷氨酰半胱氨酸合成酶的酶活性。外源H2O2引起的氧化应激增强了毕赤酵母漆酶基因的转录。外源H2O2胁迫对漆酶基因表达的刺激进一步促进了谷胱甘肽依赖性抗氧化系统相关基因的转录诱导，包括PpYAP1、PpGPX1、PpPMP20、PpGLR1和PpGSH1。综上所述，毕赤酵母中漆酶基因的表达可以通过刺激以谷胱甘肽为基础的抗氧化系统来保护细胞免受氧化损伤，从而增强酵母对h2o2介导的氧化应激的抵抗力。
Laccase is a copper-containing polyphenol oxidase that has great potential in industrial and biotechnological applications. Previous research has suggested that fungal laccase may be involved in the defense against oxidative stress, but there is little direct evidence supporting this hypothesis, and the mechanism by which laccase protects cells from oxidative stress also remains unclear. Here, we report that the expression of the laccase gene from white rot fungus in Pichia pastoris can significantly enhance the resistance of yeast to H2O2-mediated oxidative stress. The expression of laccase in yeast was found to confer a strong ability to scavenge intracellular H2O2 and to protect cells from lipid oxidative damage. The mechanism by which laccase gene expression increases resistance to oxidative stress was then investigated further. We found that laccase gene expression in Pichia pastoris could increase the level of glutathione-based antioxidative activity, including the intracellular glutathione levels and the enzymatic activity of glutathione peroxidase, glutathione reductase, and gamma-glutamylcysteine synthetase. The transcription of the laccase gene in Pichia pastoris was found to be enhanced by the oxidative stress caused by exogenous H2O2. The stimulation of laccase gene expression in response to exogenous H2O2 stress further contributed to the transcriptional induction of the genes involved in the glutathione-dependent antioxidative system, including PpYAP1, PpGPX1, PpPMP20, PpGLR1, and PpGSH1. Taken together, these results suggest that the expression of the laccase gene in Pichia pastoris can enhance the resistance of yeast to H2O2-mediated oxidative stress by stimulating the glutathione-based antioxidative system to protect the cell from oxidative damage.