FUNCTIONAL DOMAINS OF THE DROSOPHILA ENGRAILED PROTEIN
FUNCTIONAL DOMAINS OF THE DROSOPHILA ENGRAILED PROTEIN
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DOI：
10.1002/j.1460-2075.1993.tb05934.x
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发表时间：
1993-07-01
期刊：
影响因子：
11.4
通讯作者：
MANLEY, JL
中科院分区：
文献类型：
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作者：
HAN, KY;MANLEY, JL
我们研究了果蝇同源结构域蛋白Engrailed（En）的转录活性，通过使用瞬时表达试验，采用施耐德L2细胞。发现En非常强烈地抑制由多种不同激活蛋白激活的启动子。然而，不像另一个果蝇同源结构域含有阻遏物，甚至跳过（夏娃），En是无法抑制几个基本的启动子的激活表达的情况下的活动。这些研究结果表明，En是一个特定的抑制剂激活转录，并建议，En可能抑制转录不同的机制比夏娃，也许是通过干扰转录激活因子和一般的转录机器之间的相互作用。通过分析各种En突变体的特性，我们鉴定了由55个残基组成的最小阻遏结构域，其在与异源DNA结合结构域融合时可以起作用。 类似于在果蝇阻遏物Eve和Kruppel中鉴定的阻遏结构域，En阻遏结构域富含丙氨酸残基（26%），但与这些其他结构域不同，其是中等带电的（6个精氨酸残基和3个谷氨酸残基）。还鉴定了在某些情况下可能在转录激活中起作用的En的单独区域。
We have studied the transcriptional activity of the Drosophila homeodomain protein Engrailed (En) by using a transient expression assay employing Schneider L2 cells. En was found to very strongly repress promoters activated by a variety of different activator proteins. However, unlike another Drosophila homeodomain-containing repressor, Even-skipped (Eve), En was unable to repress the activity of several basal promoters in the absence of activator expression. These findings indicate that En is a specific repressor of activated transcription, and suggest that En may repress transcription by a different mechanism than Eve, perhaps by interfering with interactions between transcriptional activators and the general transcription machinery. By analyzing the properties of a variety of En mutants, we identified a minimal repression domain composed of 55 residues, which can function when fused to a heterologous DNA binding domain. Like repression domains identified in the Drosophila repressors Eve and Kruppel, the En repression domain is rich in alanine residues (26%), but unlike these other domains, is moderately charged (six arginine and three glutamic acid residues). Separate regions of En that may in some circumstances function in transcriptional activation were also identified.