Yeast SNF1 protein kinase interacts with SIP4, a C-6 zinc cluster transcriptional activator: A new role for SNF1 in the glucose response
Yeast SNF1 protein kinase interacts with SIP4, a C-6 zinc cluster transcriptional activator: A new role for SNF1 in the glucose response
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DOI：
10.1128/mcb.16.5.1921
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发表时间：
1996-05-01
影响因子：
5.3
通讯作者：
Carlson, M
中科院分区：
文献类型：
--
作者：
Lesage, P;Yang, XL;Carlson, M
SNF 1蛋白激酶在植物和哺乳动物中广泛保守，在酿酒酵母中，SNF 1是响应葡萄糖剥夺的葡萄糖抑制基因表达所必需的。先前的研究支持SNF 1在缓解转录抑制中的作用，在此，我们报告了SNF 1调节转录激活因子SIP 4的功能的证据，SIP 4是在双杂交筛选中鉴定的与SNF 1相互作用的，预测的96-kDa SIP 4蛋白的N末端与转录激活因子GAL 4家族的DNA结合结构域同源，C-6锌簇与卷曲螺旋基序相邻。C末端包含一个亮氨酸拉链基序和一个酸性区域，当与DNA结合时，LexA-SIP 4融合体激活报告基因的转录。SIP 4的转录激活受葡萄糖调节，并依赖于SNF 1蛋白激酶。此外，SIP 4是差异磷酸化响应葡萄糖的可用性，磷酸化需要SNF 1，这些研究结果表明，SNF 1激酶与转录激活因子相互作用，以调节其活性，并提供了第一个直接证据SNF 1的作用，激活转录响应葡萄糖限制。
The SNF1 protein kinase has been widely conserved in plants and mammals, In Saccharomyces cerevisiae, SNF1 is essential for expression of glucose-repressed genes in response to glucose deprivation. Previous studies supported a role for SNF1 in relieving transcriptional repression, Here, we report evidence that SNF1 modulates function of a transcriptional activator, SIP4, which was identified in a two-hybrid screen for interaction with SNF1, The N terminus of the predicted 96-kDa SIP4 protein is homologous to the DNA-binding domain of the GAL4 family of transcriptional activators, with a C-6 zinc cluster adjacent to a coiled-coil motif. The C terminus contains a leucine zipper motif and an acidic region, When bound to DNA, a LexA-SIP4 fusion activates transcription of a reporter gene. Transcriptional activation by SIP4 is regulated by glucose and depends on the SNF1 protein kinase. Moreover, SIP4 is differentially phosphorylated in response to glucose availability, and phosphorylation requires SNF1, These findings suggest that the SNF1 kinase interacts with a transcriptional activator to modulate its activity and provide the first direct evidence for a role of SNF1 in activating transcription in response to glucose limitation.