A synthetic homeodomain binding site acts as a cell type specific, promoter specific enhancer in Drosophila embryos.
A synthetic homeodomain binding site acts as a cell type specific, promoter specific enhancer in Drosophila embryos.
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合成的同源域结合位点在果蝇胚胎中充当细胞类型特异性、启动子特异性增强子。
DOI：
10.1002/j.1460-2075.1990.tb07438.x
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
O'Farrell,PH
中科院分区：
文献类型：
--
作者：
Vincent,JP;Kassis,JA;O'Farrell,PH
最初定义为Engrailed蛋白的共有结合位点的DNA序列也被几种其他同源结构域蛋白识别，并介导这些调节因子在转染的组织培养细胞中的转录作用。在这里，我们表明，这些合成的结合位点有一个更受限制的和特定的能力，以提高转录时，在转化的胚胎。有几个同源结构域结合位点连接到fushi tarazu或engrailed启动子的构建体在转化的胚胎中是沉默的。然而，当连接到热休克蛋白70启动子，该网站特异性激活神经胶质细胞中的转录。结合位点中的单碱基对突变的效应表明激活由同源结构域蛋白介导。我们认为，这种特定的表达模式的结果，在热休克蛋白70启动子片段和同源结构域结合位点的序列的联合行动。由于组织培养转染试验未显示同源结构域蛋白对启动子激活的严格限制，因此似乎转基因胚胎中明显的辅助现象对功能同源同源结构域调节剂作用的特异性有重要贡献。
A DNA sequence initially defined as a consensus binding site for the Engrailed protein is also recognized by several other homeodomain proteins and mediates the transcriptional action of these regulators in transfected tissue culture cells. Here we show that these synthetic binding sites have a more restricted and specific ability to enhance transcription when assayed in transformed embryos. Several constructs with the homeodomain binding sites linked to the fushi tarazu or engrailed promoters are silent in transformed embryos. However, when linked to the hsp70 promoter, the sites specifically activate transcription in glial cells. The effect of single base pair mutations in the binding sites suggests that activation is mediated by homeodomain protein(s). We suggest that this specific pattern of expression results from combined action at sequences within the hsp70 promoter fragment and the homeodomain binding sites. Since the tissue culture transfection assay does not show such rigid constraints on promoter activation by homeodomain proteins, it appears that subsidiary phenomena apparent in the transgenic embryos contribute importantly to the specificity of action of functionally homologous homeodomain regulators.