Two Putative Cypovirus-Encoded miRNAs Co-regulate the Host Gene of GTP-Binding Nuclear Protein Ran and Facilitate Virus Replication

作者：Lin Su, Yongsheng Wang, Ze Zhao, Wanming Wu, Yun Su, Zhendong Zhang, Manman Shen, Ping Wu, Heying Qian, Xijie Guo · 发表于：Frontiers in Physiology · 年份：2021 · DOI：10.3389/fphys.2021.663482 · 被引用次数：12 · 研究领域：Plant Virus Research Studies、RNA Research and Splicing、RNA Interference and Gene Delivery

microRNA (miRNA) plays important roles in regulating various biological processes, including host-pathogen interaction. Recent studies have demonstrated that virus-encoded miRNAs can manipulate host gene expression to ensure viral effective multiplication. Bombyx mori cypovirus (BmCPV), a double-stranded RNA virus with a segmented genome, is one of the important pathogens for the economically important insect silkworm. Our present study indicated that two putative miRNAs encoded by BmCPV could promote viral replication by inhibiting the gene expression of B. mori GTP-binding nuclear protein Ran ( BmRan ), an essential component of the exportin-5-mediated nucleocytoplasmic transport of small RNAs. BmCPV-miR-1 and BmCPV-miR-3 are two of the BmCPV-encoded miRNAs identified in our previous studies. BmRan is a common target gene of them with binding sites all located in the 3′-untranslated region (3′-UTR) of its mRNA. The expression levels of the two miRNAs in the midgut of larvae infected with BmCPV gradually increased with the advance of infection, while the expression of the target gene BmRan decreased gradually. The miRNAs and the recombinant target gene consisting of reporter gene mCherry and 3′-UTR of BmRan mRNA were expressed in HEK293T cells for validating the interaction between the miRNAs and the target gene. qRT-PCR results revealed that BmCPV-miR-1 and BmCPV-miR-3 negatively regulate target gene expression not only separately but also cooperatively by binding to the 3′...