RNA editing in Trypanosoma brucei: characterization of gRNA U-tail interactions with partially edited mRNA substrates.
RNA editing in Trypanosoma brucei: characterization of gRNA U-tail interactions with partially edited mRNA substrates.
复制标题
布氏锥虫中的 RNA 编辑：gRNA U 尾与部分编辑的 mRNA 底物相互作用的表征。
DOI：
10.1093/nar/29.3.703
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发表时间：
2001
影响因子：
14.9
通讯作者：
Koslowsky,DJ
中科院分区：
文献类型：
--
作者：
Leung,SS;Koslowsky,DJ
引导 RNA (gRNA) 是布氏锥虫 RNA 编辑反应的关键成分，指导尿苷酸 (U) 残基的插入和删除。 gRNA 分析揭示了三个功能元件。 gRNA 的 5' 端包含锚定点，负责选择并结合预编辑的 mRNA。第二个元素（引导区域）提供编辑所需的信息。 gRNA 的 3' 端是一个未编码的 U 尾，其功能尚不清楚。然而，用于编辑的切割连接模型表明，U 尾与编辑位点上游富含嘌呤的区域结合，从而加强相互作用并保留 5' 切割产物。我们之前的研究表明，U 尾与上游序列相互作用，可能在稳定和束缚中发挥作用。这些研究还表明，U 尾相互作用涉及随后要编辑的 mRNA 区域。这就提出了一个问题：当编辑沿 3′→5′ 方向进行时，mRNA-U-tail 相互作用会发生什么。我们检查了 gCYb-558 及其 U 尾与 5'CYbUT 和两个部分编辑的 5'CYb 底物的相互作用。我们的结果表明 U 尾的 3' 端与所有三种 mRNA 中的相同序列相互作用。使用交联数据预测的二级结构表明，随着编辑的进行，相似的结构得以维持。这些结果表明，U 尾的作用可能还涉及重要二级结构基序的维持。
Guide RNAs (gRNAs), key components of the RNA editing reaction inTrypanosoma brucei, direct the insertion and deletion of uridylate (U) residues. Analyses of gRNAs reveal three functional elements. The 5′-end of the gRNA contains the anchor, which is responsible for selection and binding to the pre-edited mRNA. The second element (the guiding region) provides the information required for editing. At the 3′-end of the gRNA is a non-encoded U-tail, whose function remains unclear. However, the cleavage–ligation model for editing proposes that the U-tail binds to purine-rich regions upstream of editing sites, thereby strengthening the interaction and holding onto the 5′ cleavage product. Our previous studies demonstrated that the U-tail interacts with upstream sequences and may play roles in both stabilization and tethering. These studies also indicated that the U-tail interactions involved mRNA regions that were to be subsequently edited. This raised the question of what happens to the mRNA–U-tail interaction as editing proceeds in the 3′→5′ direction. We examined gCYb-558 and its U-tail interaction with 5′CYbUT and two partially edited 5′CYb substrates. Our results indicate that the 3′-end of the U-tail interacts with the same sequence in all three mRNAs. Predicted secondary structures using crosslinking data suggest that a similar structure is maintained as editing proceeds. These results indicate that the role of the U-tail may also involve maintenance of important secondary structure motifs.