RNA silencing and RNA decay are functionally interlaced, regulate gene expression and play a pivotal role in antiviral responses. As a counter-defensive strategy, many plant and mammalian viruses encode suppressors which interfere with both mechanisms. However, the protein interactions that connect these pathways remain elusive. Previous work reported that RNA silencing suppressors from different potyviruses, together with translation initiation factors EIF(iso)4E, interacted with the C-terminal region of the tobacco exoribonuclease RRP6-like 2, a component of the RNA decay exosome complex. Here, we investigate whether other viral silencing suppressors and cellular proteins might also bind RRP6-like exoribonucleases. A candidate search approach based on yeast two-hybrid protein interaction assays showed that three other unrelated viral suppressors, two from plant viruses and one from a mammalian virus, bound the C-terminus of the tobacco RRP6-like 2, the full-length of the Arabidopsis RRP6L1 protein and its C-terminal region. In addition, RRP6-like proteins were found to interact with members of the cellular double-stranded RNA-binding protein (DRB) family involved in RNA silencing. The C-terminal regions of RRP6L proteins are engaged in homotypic and heterotypic interactions and were predicted to be disordered. Collectively, these results suggest a protein interaction network that connects components of RNA decay and RNA silencing that is targeted by viral silencing suppressors.

RNA沉默和RNA衰变在功能上交织在一起，调节基因表达并在抗病毒反应中起关键作用。作为一种反防御策略，许多植物和哺乳动物病毒都编码会干扰这两种机制的抑制剂。但是，连接这些途径的蛋白质相互作用仍然难以捉摸。先前的工作报告说，来自不同马铃薯病毒的RNA沉默抑制剂与翻译起始因子EIF（iso）4E一起与烟草外切核糖核酸酶RRP6-like 2的C端区域相互作用，后者是RNA衰减外泌体复合物的一个组成部分。在这里，我们调查其他病毒沉默抑制剂和细胞蛋白是否也可能结合RRP6样外切核糖核酸酶。一种基于酵母双杂交蛋白相互作用测定的候选搜索方法表明，其他三种不相关的病毒抑制剂 其中两种来自植物病毒，另一种来自哺乳动物病毒，它们结合了烟草RRP6样2的C端，拟南芥RRP6L1蛋白的全长及其C端区域。此外，发现RRP6样蛋白与参与RNA沉默的细胞双链RNA结合蛋白（DRB）家族成员相互作用。RRP6L蛋白的C端区域参与同型和异型相互作用，并被认为是无序的。总的来说，这些结果表明蛋白质相互作用网络连接了病毒沉默抑制剂所靶向的RNA衰变和RNA沉默的组成部分。发现类似RRP6的蛋白与参与RNA沉默的细胞双链RNA结合蛋白（DRB）家族成员相互作用。RRP6L蛋白的C端区域参与同型和异型相互作用，并被认为是无序的。总的来说，这些结果表明蛋白质相互作用网络连接了病毒沉默抑制剂所靶向的RNA衰变和RNA沉默的组成部分。发现类似RRP6的蛋白质与参与RNA沉默的细胞双链RNA结合蛋白（DRB）家族成员相互作用。RRP6L蛋白的C端区域参与同型和异型相互作用，并被认为是无序的。总的来说，这些结果表明，蛋白质相互作用网络连接了病毒沉默抑制剂所靶向的RNA衰变和RNA沉默的组成部分。