Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, China.
College of Life Science, Shanxi University, Taiyuan, Shanxi, China.
RNA Biol. 2023 Jan;20(1):323-333. doi: 10.1080/15476286.2023.2223484.
RNA interference (RNAi) is a specific post-transcriptional gene-silencing phenomenon, which plays an important role in the regulation of gene expression and the protection from transposable elements in eukaryotic organisms. In , RNAi can be induced by microRNA (miRNA), endogenous small interfering RNA (siRNA), or exogenous siRNA. However, the biogenesis of miRNA and siRNA in these RNAi pathways is aided by the double-stranded RNA binding proteins (dsRBPs) Loquacious (Loqs)-PB, Loqs-PD or R2D2. In this study, we identified three alternative splicing variants of , namely , -, and - in the orthopteran . We performed and experiments to study the roles of the three Loqs variants in the miRNA- and siRNA-mediated RNAi pathways. Our results show that Loqs-PB assists the binding of pre-miRNA to Dicer-1 to lead to the cleavage of pre-miRNA to yield matured miRNA in the miRNA-mediated RNAi pathway. In contrast, different Loqs proteins participate in different siRNA-mediated RNAi pathways. In exogenous siRNA-mediated RNAi pathway, binding of Loqs-PA or LmLoqs-PB to exogenous dsRNA facilitates the cleavage of dsRNA by Dicer-2, whereas in endogenous siRNA-mediated RNAi pathway, binding of Loqs-PB or Loqs-PC to endogenous dsRNA facilitates the cleavage of dsRNA by Dicer-2. Our findings provide new insights into the functional importance of different Loqs proteins derived from alternative splicing variants of in achieving high RNAi efficiency in different RNAi pathways in insects.
RNA 干扰 (RNAi) 是一种特定的转录后基因沉默现象，在真核生物中基因表达的调控和转座元件的保护中起着重要作用。在这里，RNAi 可以被 microRNA (miRNA)、内源性小干扰 RNA (siRNA) 或外源性 siRNA 诱导。然而，miRNA 和 siRNA 在这些 RNAi 途径中的生物发生是由双链 RNA 结合蛋白 (dsRBPs) Loquacious (Loqs)-PB、Loqs-PD 或 R2D2 辅助的。在本研究中，我们在直翅目昆虫中鉴定出 基因的三种选择性剪接变体，即 、- 和 -。我们进行了 和 实验，以研究三种 Loqs 变体在 miRNA 和 siRNA 介导的 RNAi 途径中的作用。我们的结果表明，Loqs-PB 协助 pre-miRNA 与 Dicer-1 结合，导致 pre-miRNA 被切割，从而在 miRNA 介导的 RNAi 途径中产生成熟的 miRNA。相比之下，不同的 Loqs 蛋白参与不同的 siRNA 介导的 RNAi 途径。在外源 siRNA 介导的 RNAi 途径中，Loqs-PA 或 LmLoqs-PB 与外源 dsRNA 的结合促进 Dicer-2 对 dsRNA 的切割，而在内源 siRNA 介导的 RNAi 途径中，Loqs-PB 或 Loqs-PC 与内源 dsRNA 的结合促进 Dicer-2 对 dsRNA 的切割。我们的发现为不同 Loqs 蛋白在不同 RNAi 途径中实现高 RNAi 效率的功能重要性提供了新的见解，这些蛋白来自 基因的选择性剪接变体。
