Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003 Barcelona, Spain.
RNA. 2010 Apr;16(4):817-27. doi: 10.1261/rna.1712910. Epub 2010 Feb 24.
LSm1-7 complexes promote cellular mRNA degradation, in addition to translation and replication of positive-strand RNA viruses such as the Brome mosaic virus (BMV). Yet, how LSm1-7 complexes act on their targets remains elusive. Here, we report that reconstituted recombinant LSm1-7 complexes directly bind to two distinct RNA-target sequences in the BMV genome, a tRNA-like structure at the 3'-untranslated region and two internal A-rich single-stranded regions. Importantly, in vivo analysis shows that these sequences regulate the translation and replication of the BMV genome. Furthermore, both RNA-target sequences resemble those found for Hfq, the LSm counterpart in bacteria, suggesting conservation through evolution. Our results provide the first evidence that LSm1-7 complexes interact directly with viral RNA genomes and open new perspectives in the understanding of LSm1-7 functions.
LSm1-7 复合物除了促进正链 RNA 病毒（如 Bromemosaic 病毒（BMV））的翻译和复制外，还能促进细胞 mRNA 的降解。然而，LSm1-7 复合物如何作用于其靶标仍然难以捉摸。在这里，我们报告说，重新组装的重组 LSm1-7 复合物直接结合到 BMV 基因组中的两个不同的 RNA 靶序列上，一个是在 3'-非翻译区的 tRNA 样结构，另两个是内部富含 A 的单链区。重要的是，体内分析表明这些序列调节 BMV 基因组的翻译和复制。此外，这两个 RNA 靶序列与细菌中 LSm 的对应物 Hfq 中的序列相似，这表明了进化过程中的保守性。我们的研究结果首次提供了 LSm1-7 复合物与病毒 RNA 基因组直接相互作用的证据，并为理解 LSm1-7 功能提供了新的视角。
