Glucose derepression of gluconeogenic enzymes in Saccharomyces cerevisiae correlates with phosphorylation of the gene activator Cat8p
Glucose derepression of gluconeogenic enzymes in Saccharomyces cerevisiae correlates with phosphorylation of the gene activator Cat8p
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酿酒酵母中糖异生酶的葡萄糖去抑制与基因激活剂 Cat8p 的磷酸化相关
DOI：
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发表时间：
1997
影响因子：
5.3
通讯作者：
K. Entian
中科院分区：
文献类型：
--
作者：
F. Randez;N. Bojunga;M. Proft;K. Entian
Cat 8 p锌簇蛋白对于具有不可发酵碳源的酿酒酵母的生长是必需的。CAT 8基因的表达受到主要由Mig 1 p引起的葡萄糖抑制。出乎意料的是，CAT 8启动子内Mig 1 p结合基序的缺失并没有增加CAT 8的转录;此外，它导致CAT 8启动子激活的丧失。用启动子测试质粒的插入实验证实，该调节性20-bp元件也影响葡萄糖阻遏和去阻遏。这一发现表明该启动子区域的上游激活功能，这是Mig 1 p独立的，因为delta mig 1突变体仍然能够去抑制CAT 8启动子。没有其他假定的结合位点，如Hap 2/3/4/5 p位点和Abf 1 p共有位点对葡萄糖调节的CAT 8表达有功能。Cat 8 p与Gal 4p DNA结合结构域的融合介导的转录激活。这种激活能力仍受碳源调节，并依赖于Cat 1 p（Snf 1 p）蛋白激酶，提示Cat 8 p需要翻译后修饰才能发挥其基因激活功能。事实上，十二烷基硫酸钠凝胶上的蛋白质印迹分析揭示了一个单一的带（Cat 8 pI）与葡萄糖生长的细胞的粗提物，而三个带（Cat 8 pI，-II，和-III）被确定在去阻遏细胞。解阻遏特异性Cat 8 pII和-III导致差异磷酸化，如磷酸酶治疗所示。只有最广泛的磷酸化修饰（Cat 8 pIII）依赖于Cat 1 p（Snf 1 p）激酶，表明另一种蛋白激酶负责Cat 8 pII的修饰。Cat 8 pIII的发生与致炎酶（磷酸烯醇式丙酮酸羧激酶和果糖-1，6-二磷酸酶）和致炎PCK 1 mRNA的去阻遏密切相关。此外，葡萄糖触发Cat 8 pIII的去磷酸化，但这并不依赖于先前描述的参与转化酶抑制的Glc 7 p（Cid 1 p）磷酸酶。这些结果证实了我们目前的模型，即葡萄糖去阻遏的致突变基因需要Cat 8 p磷酸化，并另外表明，一个仍然未知的转录激活因子也参与其中。
The Cat8p zinc cluster protein is essential for growth of Saccharomyces cerevisiae with nonfermentable carbon sources. Expression of the CAT8 gene is subject to glucose repression mainly caused by Mig1p. Unexpectedly, the deletion of the Mig1p-binding motif within the CAT8 promoter did not increase CAT8 transcription; moreover, it resulted in a loss of CAT8 promoter activation. Insertion experiments with a promoter test plasmid confirmed that this regulatory 20-bp element influences glucose repression and derepression as well. This finding suggests an upstream activating function of this promoter region, which is Mig1p independent, as delta mig1 mutants are still able to derepress the CAT8 promoter. No other putative binding sites such as a Hap2/3/4/5p site and an Abf1p consensus site were functional with respect to glucose-regulated CAT8 expression. Fusions of Cat8p with the Gal4p DNA-binding domain mediated transcriptional activation. This activation capacity was still carbon source regulated and depended on the Cat1p (Snf1p) protein kinase, which indicated that Cat8p needs posttranslational modification to reveal its gene-activating function. Indeed, Western blot analysis on sodium dodecyl sulfate-gels revealed a single band (Cat8pI) with crude extracts from glucose-grown cells, whereas three bands (Cat8pI, -II, and -III) were identified in derepressed cells. Derepression-specific Cat8pII and -III resulted from differential phosphorylation, as shown by phosphatase treatment. Only the most extensively phosphorylated modification (Cat8pIII) depended on the Cat1p (Snf1p) kinase, indicating that another protein kinase is responsible for modification form Cat8pII. The occurrence of Cat8pIII was strongly correlated with the derepression of gluconeogenic enzymes (phosphoenolpyruvate carboxykinase and fructose-1,6-bisphosphatase) and gluconeogenic PCK1 mRNA. Furthermore, glucose triggered the dephosphorylation of Cat8pIII, but this did not depend on the Glc7p (Cid1p) phosphatase previously described as being involved in invertase repression. These results confirm our current model that glucose derepression of gluconeogenic genes needs Cat8p phosphorylation and additionally show that a still unknown transcriptional activator is also involved.
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DOI：
10.1002/j.1460-2075.1994.tb06933.x
发表时间：
1994-12
期刊：
The EMBO Journal
影响因子：
--
作者：
Xiaolu Yang;Rong Jiang;M. Carlson
通讯作者：
Xiaolu Yang;Rong Jiang;M. Carlson
通过双杂交系统鉴定的蛋白激酶底物。
DOI：
10.1126/science.1496382
发表时间：
1992
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Yang,X;Hubbard,EJ;Carlson,M
通讯作者：
Carlson,M
酿酒酵母的果糖双磷酸酶。
影响因子：
5.6
作者：
Sedivy,JM;Fraenkel,DG
通讯作者：
Fraenkel,DG
影响因子：
3.5
作者：
KLEBE, RJ;HARRISS, JV;DOUGLAS, MG
通讯作者：
DOUGLAS, MG
GAL83 的遗传和分子特征：其与酿酒酵母中参与葡萄糖抑制的其他基因的相互作用和相似性。
影响因子：
3.3
作者：
Erickson,JR;Johnston,M
通讯作者：
Johnston,M