Short-range transcriptional repressors mediate both quenching and direct repression within complex loci in Drosophila
Short-range transcriptional repressors mediate both quenching and direct repression within complex loci in Drosophila
复制标题
DOI：
10.1101/gad.10.6.700
复制
发表时间：
1996-03-15
影响因子：
10.5
通讯作者：
Levine, M
中科院分区：
文献类型：
--
作者：
Gray, S;Levine, M
早期的果蝇胚胎提供了一个独特的系统，用于分析转录抑制，因为广泛的阻遏物分布在空间上不同的模式。Kruppel（Kr）和snail（sna）是两种锌指抑制子，分别对中胚层的分裂和中胚层/神经外胚层边界的建立起重要作用。这两个阻遏物的背景下，含有模块化的启动子和不同的转录报告基因的合成基因复合物进行了检查。这些研究表明，Kr和sna的功能作为短程阻遏物，它可以介导淬灭或直接阻遏的转录复合物，这取决于阻遏位点的位置。当位于上游增强子内时，阻遏物局部淬灭附近的激活物，并允许其他增强子与转录复合物相互作用（增强子自主性）。相反，当与启动子近端区域结合时，阻遏物以显性方式发挥功能并阻断多个增强子。局部淬灭和显性阻遏需要紧密联系（
The early Drosophila embryo provides a unique system for the analysis of transcriptional repression since a broad spectrum of repressors are distributed in spatially distinct patterns. Kruppel (Kr) and snail (sna), two zinc finger repressors, are essential for segmentation and for the establishment of the mesoderm/neuroectoderm boundary, respectively. Both repressors were examined in the context of synthetic gene complexes containing modular promoters and divergently transcribed reporter genes. These studies indicate that Kr and sna function as short-range repressors, which can mediate either quenching or direct repression of the transcription complex, depending on the location of repressor sites. When located within an upstream enhancer, the repressor locally quenches nearby activators and permits other enhancers to interact with the transcription complex (enhancer autonomy). In contrast, when bound to promoter-proximal regions the repressor functions in a dominant fashion and blocks multiple enhancers. Local quenching and dominant repression require close linkage (