AUTOREGULATION OF A SEGMENTATION GENE IN DROSOPHILA - COMBINATORIAL INTERACTION OF THE EVEN-SKIPPED HOMEO BOX PROTEIN WITH A DISTAL ENHANCER ELEMENT
AUTOREGULATION OF A SEGMENTATION GENE IN DROSOPHILA - COMBINATORIAL INTERACTION OF THE EVEN-SKIPPED HOMEO BOX PROTEIN WITH A DISTAL ENHANCER ELEMENT
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DOI：
10.1101/gad.5.2.265
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发表时间：
1991-02-01
影响因子：
10.5
通讯作者：
LEVINE, M
中科院分区：
文献类型：
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作者：
JIANG, J;HOEY, T;LEVINE, M
在果蝇中，许多模式基因的表达都涉及到自调节，但这一过程的分子细节在很大程度上是未知的。在分割基因甚至跳过（eve）的情况下，自调节对于原肠胚形成开始时基因表达的尖锐条纹的规范是重要的。在这里，我们使用DNA结合和p转化分析的组合来表征负责自动调节的顺式和反式因子。我们发现，eve的自调节至少部分是由位于eve转录起始位点上游约5kb处的100 bp最小自调节序列（MAS）介导的。包含MAS的200-bp DNA片段的多聚合可驱动最佳的自调节活性，可与位于-5.9和-5.2 kb之间的天然远端增强子元件相媲美。MAS包含两个eve蛋白结合位点，以及早期胚胎中存在的两个核因子的结合位点。这些结合位点的定向诱变表明eve蛋白和核因子都是自我调节所必需的。这些结果证明了eve蛋白与其他转录因子联合作用以增强其自身的表达。
Autoregulation has been implicated in the expression of many patterning genes in Drosophila, but the molecular details of this process are largely unknown. In the case of the segmentation gene even-skipped (eve), autoregulation is important for the specification of sharp stripes of gene expression at the onset of gastrulation. Here, we use a combination of DNA binding and P-transformation assays to characterize the cis- and trans-acting factors responsible for autoregulation. We show that eve autoregulation is mediated, at least in part, by a 100-bp minimal autoregulatory sequence (MAS) located approximately 5 kb upstream from the eve transcription start site. Multimerization of a 200-bp DNA fragment that encompasses the MAS drives optimal autoregulatory activity, comparable to that obtained with the native distal enhancer element located between -5.9 and -5.2 kb. The MAS contains two eve protein-binding sites, as well as binding sites for two nuclear factors present in early embryos. Directed mutagenesis of these binding sites suggests that both the eve protein and nuclear factors are essential for autoregulation. These results provide evidence that the eve protein acts combinatorially with other transcription factors to enhance its own expression.