A SEQUENCE-SPECIFIC DNA-BINDING PROTEIN THAT ACTIVATES FUSHI-TARAZU SEGMENTATION GENE-EXPRESSION
A SEQUENCE-SPECIFIC DNA-BINDING PROTEIN THAT ACTIVATES FUSHI-TARAZU SEGMENTATION GENE-EXPRESSION
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DOI：
10.1101/gad.4.4.624
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发表时间：
1990-04-01
影响因子：
10.5
通讯作者：
WU, C
中科院分区：
文献类型：
--
作者：
UEDA, H;SONODA, S;WU, C
果蝇分段基因Fushi Tarazu(FTZ)在细胞胚胎期以七条横纹的方式表达，这些横纹与节段原基不一致，跨越交替的节段边界。斑马元件是一个位于FTZ翻译起点上游的740个碱基对的DNA序列，当被引入果蝇基因组时，它指导LacZ的条带表达。我们纯化了一种序列特异性DNA结合因子FTZ-F1，它与斑马元件内的两个位点以及FTZ蛋白编码序列中的两个位点结合。FTZ-F1的DNA结合活性首先在1.5-4小时的胚胎提取液中检测到，与FTZ在条纹中的表达时间一致；在胚胎晚期、幼虫和成虫阶段，FTZ-F1的DNA结合活性在再次出现之前减弱。当斑马元件中的FTZ-F1结合序列中的一个被2或4碱基替换突变时，在体外与FTZ-F1的结合被破坏，转化胚胎中LacZ的表达强度降低，尤其是在第1、2、3和6条条纹中。结果表明，FTZ-F1是FTZ基因正常运行所必需的转录激活剂。
The Drosophila segmentation gene fushi tarazu (ftz) is expressed at the cellular blastoderm stage in a pattern of seven transverse stripes; the stripes lie out of register with the segmental primordia, spanning alternate segmental boundaries. The zebra element, a 740-bp DNA sequence upstream of the ftz translational start, directs striped expression of lacZ when introduced into the fly genome. We have purified to homogeneity a sequence-specific DNA-binding factor, FTZ-F1, that binds to two sites located within the zebra element and to two sites within the ftz protein-coding sequence. FTZ-F1 DNA-binding activity is first detected in extracts of 1.5- to 4-hr embryos, coincident with the time of ftz expression in stripes; the activity the diminishes before reappearing during late embryo, larval, and adult stages. When one of the FTZ-F1-binding sequences in the zebra element is mutated by 2- or 4-base substitutions, the binding to FTZ-F1 is disrupted in vitro, and the intensity of lacZ expression is reduced in transformed embryos, especially in stripes 1, 2, 3, and 6. The results suggest that FTZ-F1 is a transcriptional activator necessary for the proper of the ftz gene.