identification of drei as an antiviral factor regulated by rlr signaling pathway识别drei作为抗病毒因子受rlr信号通路.pdfVIP

Identification of DreI as an Antiviral Factor Regulated by RLR Signaling Pathway Shun Li, Fan Sun, Yi-Bing Zhang, Jian-Fang Gui, Qi-Ya Zhang* State Key Laboratory of Freshwater Ecology and Biotechnology, Wuhan Center for Developmental Biology, Institute of Hydrobiology, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Wuhan, China Abstract Background: Retinoic acid-inducible gene I (RIG-I)–like receptors (RLRs) had been demonstrated to prime interferon (IFN) response against viral infection via the conserved RLR signaling in fish, and a novel fish-specific gene, the grass carp reovirus (GCRV)-induced gene 2 (Gig2), had been suggested to play important role in host antiviral response. Methodology/Principal Findings: In this study, we cloned and characterized zebrafish Gig2 homolog (named Danio rerio Gig2-I, DreI), and revealed its antiviral role and expressional regulation signaling pathway. RT-PCR, Western blot and promoter activity assay indicate that DreI can be induced by poly I:C, spring viremia of carp virus (SVCV) and recombinant IFN (rIFN), showing that DreI is a typical ISG. Using the pivotal signaling molecules of RLR pathway, including RIG-I, MDA5 and IRF3 from crucian carp, it is found that DreI expression is regulated by RLR cascade and IRF3 plays an important role in this regulation. Furthermore, promoter mutation assay confirms that the IFN-stimulated regulatory elements (ISRE) in the 59 flanking region of DreI is essential for its induction. Finally, overexpression of DreI leads to establish a strong antiviral state against SVCV and Rana grylio virus (RGV) infection in EPC (Epithelioma papulosum cyprinid) cells. Conclusions/Significance: These data indicate that DreI is an antiviral protein, which is regulated by RLR signaling pathway. Citation: Li S, Sun F, Zhang Y-B, Gui J-F, Zhang Q-Y (2012) Identification of DreI