The impact of GAL6, GAL80, and MIG1 on glucose control of the GAL system in Saccharomyces cerevisiae
The impact of GAL6, GAL80, and MIG1 on glucose control of the GAL system in Saccharomyces cerevisiae
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DOI：
10.1111/j.1567-1364.2001.tb00012.x
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发表时间：
2001-04-01
影响因子：
3.2
通讯作者：
Nielsen, Jens
中科院分区：
文献类型：
--
作者：
Ostergaard, Simon;Walloe, Kristian O.;Nielsen, Jens
通过对不同GAL突变株的生理特性分析，研究了GAL 80基因、MIG 1基因和GAL 6基因编码的蛋白在酿酒酵母（Saccharomycescerevisiae）控制半乳糖消耗中的作用。在有氧氮限制连续培养中，以0.1 h（-1）的稀释率对CEN.PK 113- 7 D野生型菌株和Delta gal 80 Delta mig 1双突变菌株进行的动态实验显示，Delta gal 80 Delta mig 1菌株同时消耗葡萄糖和半乳糖。野生型菌株在葡萄糖存在下不消耗半乳糖。在葡萄糖-半乳糖混合物上用野生型菌株和用具有去调节GAL系统的重组菌株（Delta gal 80 Delta mig 1菌株、Delta gal 6缺失菌株、Delta gal 6 Delta gal 80 Delta mig 1三重突变体和携带GAL 4高拷贝载体的Delta gal 6 Delta gal 80 Delta mig 1三重突变体）进行需氧分批培养。通常，葡萄糖控制的减少降低了葡萄糖上的最大比生长速率，并使半乳糖上获得的乙醇产率增加超过100%。与野生型菌株相比，Delta gal 6 Delta gal 80 Delta mig 1三重突变菌株同时消耗葡萄糖和半乳糖，并且该菌株还显示出最高的乙醇产量，总乙醇产量为0.35 g g-1糖，比野生型菌株获得的葡萄糖产量高17%。GAL 80和MIG 1被证明负责GAL系统上的大部分葡萄糖控制，而GAL 6在葡萄糖控制中具有次要作用。GAL 6的缺失被证明对生物量和乙醇形成有重大影响，当细胞生长在半乳糖上时，并且从所获得的数据中，我们推测GAL 6可能参与GAL基因转录物的mRNA降解。
The role of the proteins encoded by the GAL80 gene, the MIG1 gene and the GAL6 gene in glucose control of galactose consumption by Saccharomyces cerevisiae was studied by physiological characterisation of various GAL mutant strains. Dynamic experiments with the CEN.PK 113-7D wild-type strain and a Delta gal80 Delta mig1 double-mutant strain in aerobic nitrogen-limited continuous cultivations at a dilution rate of 0.1 h(-1), showed simultaneous glucose and galactose consumption by the Delta gal80 Delta mig1 strain. The wild-type strain did not consume galactose in the presence of glucose. Aerobic batch cultivations on glucose-galactose mixtures with the wild-type strain and with recombinant strains with a de-regulated GAL system (the Delta gal80 Delta mig1 strain, a Delta gal6 deleted strain, a Delta gal6 Delta gal80 Delta mig1 triple mutant, and a Delta gal6 Delta gal80 Delta mig1 triple mutant harbouring a GAL4 high-copy vector) were carried out. Generally, a reduction of glucose control lowered the maximum specific growth rate on glucose and increased the ethanol yield obtained on galactose with more than 100%. In contrast to the wild-type strain, the Delta gal6 Delta gal80 Delta mig1 triple mutant strain consumed glucose and galactose simultaneously, and this strain also showed the highest ethanol production with an overall ethanol yield of 0.35 g g-1 sugar, which is 17% higher than the yield on glucose obtained with the wild-type strain. GAL80 and MIG1 were demonstrated to be responsible for the majority of the glucose control on the GAL system, whereas GAL6 has a minor role in glucose control. Deletion of GAL6 was shown to have a major impact on biomass and ethanol formation when cells were grown on galactose, and from the data obtained we speculate that Gal6 may be involved in mRNA degradation of the GAL gene transcripts.