High-affinity binding sites for the Deformed protein are required for the function of an autoregulatory enhancer of the Deformed gene.
High-affinity binding sites for the Deformed protein are required for the function of an autoregulatory enhancer of the Deformed gene.
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变形蛋白的高亲和力结合位点对于变形基因的自动调节增强子的功能是必需的。
DOI：
10.1101/gad.5.2.278
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发表时间：
1991
影响因子：
10.5
通讯作者：
McGinnis,W
中科院分区：
文献类型：
--
作者：
Regulski,M;Dessain,S;McGinnis,N;McGinnis,W
在果蝇发育过程中，需要同源选择基因 Deformed (Dfd) 来指定头段的身份。先前的实验表明，为了使 Dfd 节段同一性功能在表皮细胞中发挥作用，Dfd 基因必须持续表达。提供 Dfd 持续胚胎表达的一种机制是自动调节回路。在这里，我们表明，这种自动调节回路的控制很可能是由 Dfd 蛋白与 Dfd 位点 DNA 上游增强子的结合直接介导的。在 Dfd 转录单元周围的 25 kb 区域中，对 Dfd 蛋白具有最高结合亲和力的限制性片段位于上游自动调节元件约 -5 kb 的范围内。上游 DNA 的 920 bp 片段内的最小自动调节元件具有四个中度至高亲和力的 Dfd 蛋白结合位点，其中两个最高亲和力位点共享 ATCATTA 共有序列。这四个位点的位点特异性诱变导致一种元件在体外测定时对 Dfd 蛋白具有低亲和力，而在胚胎中测定时则无功能。
The homeotic selector gene Deformed (Dfd) is required to specify the identity of head segments during Drosophila development. Previous experiments have shown that for the Dfd segmental identity function to operate in epidermal cells, the Dfd gene must be persistently expressed. One mechanism that provides persistent embryonic expression of Dfd is an autoregulatory circuit. Here, we show that the control of this autoregulatory circuit is likely to be directly mediated by the binding of Dfd protein to an upstream enhancer in Dfd locus DNA. In a 25-kb region around the Dfd transcription unit, restriction fragments with the highest binding affinity for Dfd protein map within the limits of the upstream autoregulatory element at approximately -5 kb. A minimal autoregulatory element, within a 920-bp segment of upstream DNA, has four moderate- to high-affinity binding sites for Dfd protein, with the two highest affinity sites sharing an ATCATTA consensus sequence. Site-specific mutagenesis of these four sites results in an element that has low affinity for Dfd protein when assayed in vitro and is nonfunctional when assayed in embryos.