Xenopus cytoskeletal actin and human c‐fos gene promoters share a conserved protein‐binding site.
Xenopus cytoskeletal actin and human c‐fos gene promoters share a conserved protein‐binding site.
复制标题
非洲爪蟾细胞骨架肌动蛋白和人类 c-fos 基因启动子共享一个保守的蛋白质结合位点。
作者：
T. Mohun;N. Garrett;R. Treisman
非洲爪哇细胞骨架肌动蛋白基因启动子包含一个与血清反应元件(SRE)同源的20bp序列，该元件是瞬时转录人c-fos基因对血清因子作出反应所必需的。通过结合竞争、DNase I和二甲基硫酸盐(DMS)保护以及DMS干扰试验，表明这两个序列在HeLa细胞提取物中结合了相同的因子。非洲爪哇卵母细胞中也存在类似的蛋白质。含有SRE同源性的序列对于非洲爪哇和小鼠细胞中肌动蛋白启动子的构成活性是必不可少的，合成的SRE在这些细胞中作为启动子元件发挥作用。在小鼠细胞中，在血清刺激下，转染的非洲爪哇肌动蛋白和肌动蛋白/c-fos融合基因的转录都被激活。这些数据表明，SRE及其同源蛋白构成了在进化过程中高度保守的调控途径的一部分。
Xenopus laevis cytoskeletal actin gene promoters contain a 20‐bp sequence homologous to the serum response element (SRE) required for transient human c‐fos gene transcription in response to serum factors. Both sequences bind the same factor in HeLa cell extracts, as shown by binding competition, DNase I and dimethylsulphate (DMS) protection and DMS interference assays. A similar protein is present in Xenopus laevis oocytes. Sequences containing the SRE homology are essential for constitutive activity of the actin promoter in both Xenopus and mouse cells, and a synthetic SRE functions as a promoter element in these cells. In mouse cells, transcription of both transfected Xenopus actin and actin/c‐fos fusion genes is activated following serum stimulation. These data suggest that the SRE and its cognate protein form part of a regulatory pathway that has been highly conserved during evolution.