Sasaki Hiromi, Uemura Hiroshi
Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan.
Yeast. 2005 Jan 30;22(2):111-27. doi: 10.1002/yea.1198.
A complex of the transcription factors Gcr1p and Gcr2p coordinately regulates the expression of glycolytic genes in Saccharomyces cerevisiae. To understand the effects of gcr mutations on other metabolic pathways, genome-wide gene expression profiles in gcr1 and gcr2 mutants were examined. The biggest effects of gcr1 and gcr2 mutations were observed on the glycolytic genes and the expressions of most of the glycolytic genes were substantially decreased compared to those in the wild-type strain in both glucose and glycerol+lactate growth conditions. On the other hand, the expressions of genes encoding the TCA cycle and respiration were increased in gcr mutants when the cells were grown in glucose. RT-PCR analyses revealed that the expression of SIP4 and HAP5, which are known to affect the expression of some of the gluconeogenic, TCA cycle and respiratory genes, were also increased under this condition. The growth of gcr mutants on glucose was impaired by adding respiration inhibitor antimycin A, whereas the growth of the wild-type strain was not. The conversion of glucose to biomass was higher and, to the contrary, ethanol yield was lower in the gcr2 mutant compared to those in the wild-type strain. These results suggest the possibility that the gcr mutants, in which glycolytic activities are low, changed their metabolic patterns under glucose growth condition to enhance the expression of TCA cycle and respiratory genes to produce more energy.
转录因子Gcr1p和Gcr2p的复合物协同调节酿酒酵母中糖酵解基因的表达。为了了解gcr突变对其他代谢途径的影响，研究了gcr1和gcr2突变体的全基因组基因表达谱。在葡萄糖和甘油+乳酸生长条件下，gcr1和gcr2突变对糖酵解基因的影响最大，与野生型菌株相比，大多数糖酵解基因的表达大幅下降。另一方面，当细胞在葡萄糖中生长时，gcr突变体中编码三羧酸循环和呼吸作用的基因表达增加。RT-PCR分析表明，已知影响某些糖异生、三羧酸循环和呼吸基因表达的SIP4和HAP5的表达在这种条件下也增加。通过添加呼吸抑制剂抗霉素A，gcr突变体在葡萄糖上的生长受到损害，而野生型菌株的生长不受影响。与野生型菌株相比，gcr2突变体中葡萄糖向生物量的转化率更高，相反，乙醇产量更低。这些结果表明，糖酵解活性低的gcr突变体在葡萄糖生长条件下可能改变其代谢模式，以增强三羧酸循环和呼吸基因的表达，从而产生更多能量。
