Hirasawa T, Nakakura Y, Yoshikawa K, Ashitani K, Nagahisa K, Furusawa C, Katakura Y, Shimizu H, Shioya S
Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Osaka, Japan.
Appl Microbiol Biotechnol. 2006 Apr;70(3):346-57. doi: 10.1007/s00253-005-0192-6. Epub 2005 Nov 11.
To construct yeast strains showing tolerance to high salt concentration stress, we analyzed the transcriptional response to high NaCl concentration stress in the yeast Saccharomyces cerevisiae using DNA microarray and compared between two yeast strains, a laboratory strain and a brewing one, which is known as a stress-tolerant strain. Gene expression dynamically changed following the addition of NaCl in both yeast strains, but the degree of change in the gene expression level in the laboratory strain was larger than that in the brewing strain. The response of gene expression to the low NaCl concentration stress was faster than that to the high NaCl concentration stress in both strains. Expressions of the genes encoding enzymes involved in carbohydrate metabolism and energy production in both strains or amino acid metabolism in the brewing strain were increased under high NaCl concentration conditions. Moreover, the genes encoding sodium ion efflux pump and copper metallothionein proteins were more highly expressed in the brewing strain than in the laboratory strain. According to the results of transcriptome analysis, candidate genes for the creation of stress-tolerant strain were selected, and the effect of overexpression of candidate genes on the tolerance to high NaCl concentration stress was evaluated. Overexpression of the GPD1 gene encoding glycerol-3-phosphate dehydrogenase, ENA1 encoding sodium ion efflux protein, and CUP1 encoding copper metallothionein conferred high salt stress tolerance to yeast cells, and our selection of candidate genes for the creation of stress-tolerant yeast strains based on the transcriptome data was validated.
为构建对高盐浓度胁迫具有耐受性的酵母菌株，我们使用DNA微阵列分析了酿酒酵母对高氯化钠浓度胁迫的转录反应，并比较了两种酵母菌株，一种是实验室菌株，另一种是已知的耐胁迫酿造菌株。在两种酵母菌株中，添加氯化钠后基因表达均发生动态变化，但实验室菌株中基因表达水平的变化程度大于酿造菌株。在两种菌株中，基因表达对低氯化钠浓度胁迫的反应比对高氯化钠浓度胁迫的反应更快。在高氯化钠浓度条件下，两种菌株中参与碳水化合物代谢和能量产生的酶编码基因或酿造菌株中氨基酸代谢的酶编码基因的表达均增加。此外，编码钠离子外流泵和铜金属硫蛋白的基因在酿造菌株中的表达高于实验室菌株。根据转录组分析结果，选择了用于创建耐胁迫菌株的候选基因，并评估了候选基因过表达对高氯化钠浓度胁迫耐受性的影响。编码甘油-3-磷酸脱氢酶的GPD1基因、编码钠离子外流蛋白的ENA1基因和编码铜金属硫蛋白的CUP1基因的过表达赋予酵母细胞高盐胁迫耐受性，基于转录组数据选择用于创建耐胁迫酵母菌株的候选基因得到了验证。
