Moore P A, Sagliocco F A, Wood R M, Brown A J
University of Aberdeen, Marischal College, United Kingdom.
Mol Cell Biol. 1991 Oct;11(10):5330-7. doi: 10.1128/mcb.11.10.5330-5337.1991.
The regulation of glycolytic genes in response to carbon source in the yeast Saccharomyces cerevisiae has been studied. When the relative levels of each glycolytic mRNA were compared during exponential growth on glucose or lactate, the various glycolytic mRNAs were found to be induced to differing extents by glucose. No significant differences in the stabilities of the PFK2, PGK1, PYK1, or PDC1 mRNAs during growth on glucose or lactate were observed. PYK::lacZ and PGK::lacZ fusions were integrated independently into the yeast genome at the ura3 locus. The manner in which these fusions were differentially regulated in response to carbon source was similar to that of their respective wild-type loci. Therefore, the regulation of glycolytic mRNA levels is mediated at the transcriptional level. When the mRNAs are ordered with respect to the glycolytic pathway, two peaks of maximal induction are observed at phosphofructokinase and pyruvate kinase. These enzymes (i) catalyze the two essentially irreversible steps on the pathway, (ii) are the two glycolytic enzymes that are circumvented during gluconeogenesis and hence are specific to glycolysis, and (iii) are encoded by mRNAs that we have shown previously to be coregulated at the translational level in S. cerevisiae (P. A. Moore, A. J. Bettany, and A. J. P. Brown, NATO ASI Ser. Ser. H Cell Biol. 49:421-432, 1990). This differential regulation of glycolytic mRNA levels might therefore have a significant influence upon glycolytic flux in S. cerevisiae.
对酿酒酵母中糖酵解基因响应碳源的调控进行了研究。当比较在葡萄糖或乳酸上指数生长期间每种糖酵解mRNA的相对水平时，发现各种糖酵解mRNA被葡萄糖诱导的程度不同。在葡萄糖或乳酸上生长期间，未观察到PFK2、PGK1、PYK1或PDC1 mRNA稳定性的显著差异。PYK::lacZ和PGK::lacZ融合体分别整合到酵母基因组的ura3位点。这些融合体响应碳源的差异调控方式与其各自野生型位点的调控方式相似。因此，糖酵解mRNA水平的调控是在转录水平介导的。当根据糖酵解途径对mRNA进行排序时，在磷酸果糖激酶和丙酮酸激酶处观察到两个最大诱导峰。这些酶（i）催化该途径上两个基本不可逆的步骤，（ii）是糖异生过程中绕过的两种糖酵解酶，因此是糖酵解特有的，（iii）由我们先前已证明在酿酒酵母中在翻译水平上共调控的mRNA编码（P. A. Moore、A. J. Bettany和A. J. P. Brown，北约ASI系列细胞生物学49:421 - 432，1990）。因此，糖酵解mRNA水平的这种差异调控可能对酿酒酵母中的糖酵解通量有显著影响。
