Gruber Andreas R, Kilgus Carsten, Mosig Axel, Hofacker Ivo L, Hennig Wolfgang, Stadler Peter F
Institute for Theoretical Chemistry, University of Vienna, Vienna, Austria.
Mol Biol Evol. 2008 Sep;25(9):1923-30. doi: 10.1093/molbev/msn140. Epub 2008 Jun 19.
The 7SK small nuclear RNA (snRNA) is a key player in the regulation of polymerase (pol) II transcription. The 7SK RNA was long believed to be specific to vertebrates where it is highly conserved. Homologs in basal deuterostomes and a few lophotrochozoan species were only recently reported. On longer timescales, 7SK evolves rapidly with only few conserved sequence and structure motifs. Previous attempts to identify the Drosophila homolog thus have remained unsuccessful despite considerable efforts. Here we report on the discovery of arthropod 7SK RNAs using a novel search strategy based on pol III promoters, as well as the subsequent verification of its expression. Our results demonstrate that a 7SK snRNA featuring 2 highly structured conserved domains was present already in the bilaterian ancestor.
7SK小核RNA（snRNA）是聚合酶（pol）II转录调控中的关键因子。长期以来，人们一直认为7SK RNA是脊椎动物特有的，并且在脊椎动物中高度保守。直到最近才报道了基础后口动物和一些触手冠动物物种中的同源物。在更长的时间尺度上，7SK进化迅速，只有少数保守的序列和结构基序。尽管付出了巨大努力，但此前鉴定果蝇同源物的尝试均未成功。在这里，我们报告了使用基于pol III启动子的新型搜索策略发现节肢动物7SK RNA，以及随后对其表达的验证。我们的结果表明，具有2个高度结构化保守结构域的7SK snRNA在两侧对称动物的祖先中就已经存在。
