In vitro transcriptional activation by a metabolic intermediate: activation by Leu3 depends on alpha-isopropylmalate.
In vitro transcriptional activation by a metabolic intermediate: activation by Leu3 depends on alpha-isopropylmalate.
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DOI：
10.1126/science.1439822
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发表时间：
1992-11
期刊：
影响因子：
56.9
通讯作者：
J. Sze;M. Woontner;J. A. Jaehning;G. Kohlhaw
中科院分区：
文献类型：
--
作者：
J. Sze;M. Woontner;J. A. Jaehning;G. Kohlhaw
在没有亮氨酸生物合成前体α-异丙基苹果酸(α-IPM)的情况下，酵母LEU3蛋白(Leu3p)与DNA结合，并在体外提取液中作为转录抑制因子。加入α-IPM导致Leu3p依赖的转录显著增加。Leu3p还需要α-IPM的存在才能有效地与另一种转录激活剂GAL4/VP16竞争限制转录因子。因此，α-IPM的加入似乎将转录抑制物转化为激活剂。这代表了真核生物中由一个小效应分子直接转录调控的一个例子。
In the absence of the leucine biosynthetic precursor alpha-isopropylmalate (alpha-IPM), the yeast LEU3 protein (Leu3p) binds DNA and acts as a transcriptional repressor in an in vitro extract. Addition of alpha-IPM resulted in a dramatic increase in Leu3p-dependent transcription. The presence of alpha-IPM was also required for Leu3p to compete effectively with another transcriptional activator, GAL4/VP16, for limiting transcription factors. Therefore, the addition of alpha-IPM appears to convert a transcriptional repressor into an activator. This represents an example in eukaryotes of direct transcriptional regulation by a small effector molecule.