CDC19 encoding pyruvate kinase is important for high-temperature tolerance in Saccharomyces cerevisiae
CDC19 encoding pyruvate kinase is important for high-temperature tolerance in Saccharomyces cerevisiae
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DOI：
10.1016/j.nbt.2011.03.007
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发表时间：
2012-01-15
影响因子：
5.4
通讯作者：
Harashima, Satoshi
中科院分区：
文献类型：
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作者：
Benjaphokee, Suthee;Koedrith, Preeyaporn;Harashima, Satoshi
使用耐热菌株是降低发酵过程中保持最佳温度的成本的一种有前途的方法。我们对一株高温(41℃)生长(HTG(+))的酿酒酵母菌株进行了遗传研究，结果表明该菌株的HTG(+)表型是显性的，并可能受6个基因的控制，命名为HTG1至HTG6。与HTG(+)菌株相比，HTG(+)菌株在48℃的热休克条件下表现出更高的存活率。此外，HTG(+)菌株在高温下培养时海藻糖含量显著高于HTG(+)菌株，并且对干扰细胞壁形成的刚果红具有更强的抗性。这些结果表明，加强细胞壁和增加海藻糖积累相结合，可以支持高温下的生长。编码丙酮酸激酶的CDC19基因被克隆为HTG2基因。HTG(+)株的CDC19等位基因在其上游区域有5个碱基变化，在其编码区有2个碱基变化，导致其编码区无突变。有趣的是，后者的碱基变化可能是HTG(+)菌株丙酮酸激酶活性增加的原因。讨论了导致这种活性增加和HTG(+)表型的可能机制，这可能导致激活能量代谢以维持细胞内环境平衡。
Use of thermotolerant strains is a promising way to reduce the cost of maintaining optimum temperatures in the fermentation process. Here we investigated genetically a Saccharomyces cerevisiae strain showing a high-temperature (41 degrees C) growth (Htg(+)) phenotype and the result suggested that the Htg(+) phenotype of this Htg(+) strain is dominant and under the control of most probably six genes, designated HTG1 to HTG6. As compared with a Htg(+) strain, the Htg(+) strain showed a higher survival rate after exposure to heat shock at 48 degrees C. Moreover, the Htg(+) strain exhibited a significantly high content of trehalose when cultured at high temperature and stronger resistance to Congo Red, an agent that interferes with cell wall construction. These results suggest that a strengthened cell wall in combination with increased trehalose accumulation can support growth at high temperature. The gene CDC19, encoding pyruvate kinase, was cloned as the HTG2 gene. The CDC19 allele from the Htg(+) strain possessed five base changes in its upstream region, and two base changes resulting in silent mutations in its coding region. Interestingly, the latter base changes are probably responsible for the increased pyruvate kinase activity of the Htg(+) strain. The possible mechanism leading to this increased activity and to the Htg(+) phenotype, which may lead to the activation of energy metabolism to maintain cellular homeostasis, is discussed.