Abstract：
RNA silencing, a conserved gene regulatory mechanism, is critical for host resistance to viruses. Liquid-liquid phase separation (LLPS) is an important mechanism in regulating various biological processes. Emerging studies suggest RNA helicases play important roles in microRNA (miRNA) production through LLPS. In this study, we investigated the functional role of RNA helicase 20 (RH20), a DDX5 homolog in Arabidopsis thaliana, in RNA silencing and plant resistance to viruses. Our findings reveal that RH20 localizes in both the cytoplasm and nucleus, with puncta formation in the cytoplasm exhibiting liquid-liquid phase separation behavior. We demonstrate that RH20 plays positive roles in plant immunity against viruses. Further study showed that RH20 interacts with Argonaute 2 (AGO2), a key component of the RNA silencing pathway. Moreover, RH20 promotes the accumulation of both endogenous and exogenous small RNAs (sRNAs). Overall, our study identifies RH20 as a novel phase separation protein that interacting with AGO2, influencing sRNAs accumulation, and enhancing plant resistance to viruses.
摘要：
RNA沉默，保守的基因调控机制，对于宿主对病毒的抗性至关重要。液-液相分离（LLPS）是调节各种生物过程的重要机制。新兴研究表明，RNA解旋酶在通过LLPS产生microRNA（miRNA）中起重要作用。在这项研究中,我们研究了RNA解旋酶20（RH20）的功能作用，拟南芥中的DDX5同源物，RNA沉默和植物对病毒的抗性。我们的发现表明，RH20定位于细胞质和细胞核，在细胞质中形成斑点，表现出液-液相分离行为。我们证明RH20在植物抗病毒免疫中起积极作用。进一步的研究表明，RH20与Argonaute2（AGO2）相互作用，RNA沉默途径的关键组成部分。此外，RH20促进内源性和外源性小RNA(sRNA)的积累。总的来说,我们的研究确定RH20是一种新型的相分离蛋白，它与AGO2相互作用，影响sRNAs的积累，增强植物对病毒的抵抗力。
