Senior Research Fellow Center, Ehime University, Matsuyama, Ehime, Japan.
Bioorg Med Chem Lett. 2012 Feb 15;22(4):1639-42. doi: 10.1016/j.bmcl.2011.12.118. Epub 2012 Jan 2.
A strategy for rationally constructing a novel type of eukaryotic OFF-riboswitch, which ligand-dependently turns off translation mediated by an internal ribosome entry site (IRES), has been established. The theophylline-dependent IRES-based OFF-riboswitch obtained through the proposed strategy functioned well in wheat germ extract, independently from the downstream gene, indicating that it can regulate any gene. Despite the fact that it has one theophylline aptamer, its switching efficiency was as high as that of a previously reported theophylline-dependent OFF-riboswitch that was constructed by inserting three continuous theophylline aptamers into a 5' untranslated region in mRNA to downregulate the normal 5'-terminus-mediated translation. In addition, because the riboswitch part that was optimized in the theophylline-dependent IRES-based OFF-riboswitch, except for the aptamer domain, can be used as-is for other aptamer-ligand pairs, an arbitrary ligand-dependent IRES-based OFF-riboswitch is easy to construct with the corresponding well-minimized aptamer.
已经建立了一种合理构建新型真核 OFF-riboswitch 的策略，该策略依赖配体关闭由内部核糖体进入位点（IRES）介导的翻译。通过所提出的策略获得的依赖于茶碱的基于 IRES 的 OFF-riboswitch 在小麦胚提取物中功能良好，与下游基因无关，这表明它可以调节任何基因。尽管它只有一个茶碱适体，但它的开关效率与之前报道的依赖茶碱的 OFF-riboswitch 一样高，后者通过将三个连续的茶碱适体插入 mRNA 的 5'非翻译区来下调正常的 5'-末端介导的翻译。此外，由于优化的茶碱依赖性 IRES 基 OFF-riboswitch 中的 riboswitch 部分（除了适体结构域）可以原样用于其他适体配体对，因此可以使用相应的最小化适体轻松构建任意配体依赖性 IRES 基 OFF-riboswitch。
