Zhao Xiaoching, Shi Hua, Sevilimedu Aarti, Liachko Nicole, Nelson Hillary C M, Lis John T
Department of Molecular Biology and Genetics, Biotechnology Building, Cornell University, Ithaca, NY 14853, USA.
Nucleic Acids Res. 2006 Aug 7;34(13):3755-61. doi: 10.1093/nar/gkl470. Print 2006.
Heat shock factor (HSF) is a conserved and highly potent transcription activator. It is involved in a wide variety of important biological processes including the stress response and specific steps in normal development. Reagents that interfere with HSF function would be useful for both basic studies and practical applications. We selected an RNA aptamer that binds to HSF with high specificity. Deletion analysis defined the minimal binding motif of this aptamer to be two stems and one stem-loop joined by a three-way junction. This RNA aptamer interferes with normal interaction of HSF with its DNA element, which is a key regulatory step for HSF function. The DNA-binding domain plus a flanking linker region on the HSF (DL) is essential for the RNA binding. Additionally, this aptamer inhibits HSF-induced transcription in vitro in the complex milieu of a whole cell extract. In contrast to the previously characterized NF-kappaB aptamer, the HSF aptamer does not simply mimic DNA binding, but rather binds to HSF in a manner distinct from DNA binding to HSF.
热休克因子（HSF）是一种保守且高效的转录激活因子。它参与多种重要的生物学过程，包括应激反应和正常发育中的特定步骤。干扰HSF功能的试剂对于基础研究和实际应用都将是有用的。我们筛选出了一种能与HSF高度特异性结合的RNA适配体。缺失分析确定该适配体的最小结合基序为两个茎和一个通过三向连接点相连的茎环。这种RNA适配体干扰了HSF与其DNA元件的正常相互作用，而这是HSF功能的关键调控步骤。HSF上的DNA结合结构域加上侧翼连接区（DL）对于RNA结合至关重要。此外，这种适配体在全细胞提取物的复杂环境中能在体外抑制HSF诱导的转录。与先前表征的NF-κB适配体不同，HSF适配体并非简单地模拟DNA结合，而是以一种不同于DNA与HSF结合的方式与HSF结合。
