State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China.
College of Plant Protection, China Agricultural University, Beijing, China.
Elife. 2020 Mar 24;9:e53753. doi: 10.7554/eLife.53753.
Carbon catabolite repression 4 (CCR4) is a conserved mRNA deadenylase regulating posttranscriptional gene expression. However, regulation of CCR4 in virus infections is less understood. Here, we characterized a pro-viral role of CCR4 in replication of a plant cytorhabdovirus (BYSMV). The barley () CCR4 protein (HvCCR4) was identified to interact with the BYSMV phosphoprotein (P). The BYSMV P protein recruited HvCCR4 from processing bodies (PBs) into viroplasm-like bodies. Overexpression of HvCCR4 promoted BYSMV replication in plants. Conversely, knockdown of the small brown planthopper CCR4 inhibited viral accumulation in the insect vector. Biochemistry experiments revealed that HvCCR4 was recruited into N-RNA complexes by the BYSMV P protein and triggered turnover of N-bound cellular mRNAs, thereby releasing RNA-free N protein to bind viral genomic RNA for optimal viral replication. Our results demonstrate that the co-opted CCR4-mediated RNA decay facilitates cytorhabdovirus replication in plants and insects.
碳分解代谢物阻遏物 4（CCR4）是一种保守的 mRNA 脱腺苷酶，可调节转录后基因表达。然而，病毒感染中 CCR4 的调控作用还不太清楚。在这里，我们研究了 CCR4 在植物细胞弹状病毒（BYSMV）复制中的促病毒作用。大麦（）CCR4 蛋白（HvCCR4）被鉴定为与 BYSMV 磷蛋白（P）相互作用。BYSMV P 蛋白将 HvCCR4 从处理体（PBs）招募到类病毒体中。HvCCR4 的过表达促进了植物中 BYSMV 的复制。相反，褐飞虱 CCR4 的敲低抑制了昆虫载体中病毒的积累。生化实验表明，HvCCR4 被 BYSMV P 蛋白招募到 N-RNA 复合物中，并触发 N 结合的细胞 mRNA 的周转，从而释放无 RNA 的 N 蛋白与病毒基因组 RNA 结合以实现最佳病毒复制。我们的研究结果表明，共调控的 CCR4 介导的 RNA 降解有助于植物和昆虫中的细胞弹状病毒复制。
