The E3 ligase TRIM56 is a host restriction factor of Zika virus and depends on its RNA-binding activity but not miRNA regulation, for antiviral function

Yang, Darong; Li, Nan L.; Wei, Dahai; Liu, Baoming; Guo, Fang; Elbahesh, Husni; Zhang, Yunzhi; Zhou, Zhi; Chen, Guo-Yun; Li, Kui

TRIM56 is an RNA-binding protein that restricts Zika virus IFN-α or ZIKV and the increase in its expression following ZIKV infection was not strictly correlated with induction of classical ISGs (IFIT3 and ISG56), indicating different mechanism of gene expression regulation that warrants future investigation. Very recently, Seo et al. reported that in mouse macrophages Trim56 deletion did not significantly alter viral RNA TRIM56 is an RNA-binding protein that restricts Zika virus levels following ZIKV infection [50] . It should be noted that mouse is not a natural host of ZIKV and not susceptible to the virus unless with deficiencies in IFN induction and/or signaling [20, 21] . Consistent with this, our in vitro infection experiments demonstrated that three murine cell lines, MEFs, L929 and hepa1-6, all had limited permissiveness for ZIKV infection, as compared with human cell lines. Whether TRIM56 exhibits different roles in antiviral immunity between host species and/or between tissue origins in mouse will require additional study.