Mediator subunits and histone methyltransferase Set2 contribute to Ino2-dependent transcriptional activation of phospholipid biosynthesis in the yeast Saccharomyces cerevisiae
Mediator subunits and histone methyltransferase Set2 contribute to Ino2-dependent transcriptional activation of phospholipid biosynthesis in the yeast Saccharomyces cerevisiae
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DOI：
10.1007/s00438-009-0508-9
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发表时间：
2010-03-01
影响因子：
3.1
通讯作者：
Schueller, Hans-Joachim
中科院分区：
文献类型：
--
作者：
Dettmann, Anne;Jaeschke, Yvonne;Schueller, Hans-Joachim
为了激活真核基因，利用修饰染色质和募集转录机制的一般因子的几种途径。我们研究了激活酵母磷脂生物合成基因所需的因素，这取决于激活蛋白Ino 2结合到肌醇/胆碱响应元件（ICRE）上游启动子基序连同其伴侣蛋白Ino 4。我们使用了一组15个菌株，每个缺陷的非必需亚基的酵母介体复合物，并确定为受损的肌醇生物合成的med 2，med 3，med 15，med 18和med 19。在这些突变体中，ICRE依赖的基因激活降低到野生型水平的13-22%。我们还证明了介质突变体和突变体缺乏定义的组蛋白修饰（snf 1，gcn 5）和转录辅激活因子（sub1）之间的合成生长和激活缺陷。对组蛋白甲基化（set 1、set 2和dot 1）和去甲基化（jhd 1、jhd 2、gis 1、rph 1和ecm 5）缺陷突变体的分析揭示了H3 Lys 36特异性Set 2甲基转移酶对ICRE依赖性基因表达的重要性。尽管定义的介体亚基对于基因激活至关重要，但我们无法检测到它们与Ino 2的相互作用。相反，Ino 2直接结合Set 2组蛋白甲基转移酶。相互作用域的映射揭示了SET核心域的重要性，这是必要的和足够的结合Ino 2。
To activate eukaryotic genes, several pathways which modify chromatin and recruit general factors of the transcriptional machinery are utilized. We investigated the factors required for activation of yeast phospholipid biosynthetic genes, depending on activator protein Ino2 which binds to the inositol/choline-responsive element (ICRE) upstream promoter motif together with its partner protein Ino4. We used a set of 15 strains each defective for one of the non essential subunits of yeast mediator complex and identified med2, med3, med15, med18 and med19 as impaired for inositol biosynthesis. In these mutants, ICRE-dependent gene activation was reduced to 13-22% of the wild-type level. We also demonstrate synthetic growth and activation defects among mediator mutants and mutants lacking defined histone modifications (snf1, gcn5) and transcriptional coactivators (sub1). Analysis of mutants defective for histone methylation (set1, set2 and dot1) and demethylation (jhd1, jhd2, gis1, rph1 and ecm5) revealed the importance of the H3 Lys36-specific Set2 methyltransferase for ICRE-dependent gene expression. Although defined mediator subunits are critical for gene activation, we could not detect their interaction with Ino2. In contrast, Ino2 directly binds to the Set2 histone methyltransferase. Mapping of interaction domains revealed the importance of the SET core domain which was necessary and sufficient for binding Ino2.