Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 15 rue René Descartes, 67084 Strasbourg, France.
Nucleic Acids Res. 2010 Jan;38(2):370-81. doi: 10.1093/nar/gkp988. Epub 2009 Nov 11.
The C/D box scaRNA2 is predicted to guide specific 2'-O-methylation of U2 snRNA. In contrast to other SCARNA genes, SCARNA2 appears to be independently transcribed. By transient expression of SCARNA2-reporter gene constructs, we have demonstrated that this gene is transcribed by RNA polymerase II and that the promoter elements responsible for its transcription are contained within a 161 bp region upstream of the transcription start site. In mammals, we have identified four cross species conserved promoter elements, a TATA motif, an hStaf/ZNF143 binding site and two novel elements that are required for full promoter activity. Binding of the human hStaf/ZNF143 transcription factor to its target sequence is required for promoter activity, suggesting that hStaf/ZNF143 is a fundamental regulator of the SCARNA2 gene. We also showed that RNA polymerase II continues transcription past the 3'-end of the mature RNA, irrespective of the identity of the Pol II promoter. The 3'-end processing and accumulation are governed by the sole information contained in the scaRNA2 encoding region, the maturation occurring via a particular pathway incompatible with that of mRNA or snRNA production.
C/D 框 scaRNA2 被预测可指导 U2 snRNA 的特异性 2'-O-甲基化。与其他 SCARNA 基因不同，SCARNA2 似乎是独立转录的。通过瞬时表达 SCARNA2 报告基因构建体，我们已经证明该基因是由 RNA 聚合酶 II 转录的，并且负责其转录的启动子元件包含在转录起始位点上游的 161bp 区域内。在哺乳动物中，我们已经鉴定出四个跨物种保守的启动子元件，一个 TATA 基序、一个 hStaf/ZNF143 结合位点和两个新的元件，这些元件对于完全启动子活性是必需的。人 hStaf/ZNF143 转录因子与其靶序列的结合对于启动子活性是必需的，这表明 hStaf/ZNF143 是 SCARNA2 基因的基本调节剂。我们还表明，RNA 聚合酶 II 会在成熟 RNA 的 3'-末端继续转录，而不管 Pol II 启动子的身份如何。3'-末端加工和积累受 scaRNA2 编码区域中包含的唯一信息控制，成熟是通过与 mRNA 或 snRNA 产生不兼容的特定途径进行的。
