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

To determine whether TRIM56 expressed at physiologic levels impedes propagation of ZIKV, we depleted endogenous TRIM56 in HeLa cells by shRNA-mediated knockdown and evaluated the changes in viral protein expression and progeny virus production. As shown in Fig TRIM56 is an RNA-binding protein that restricts Zika virus 3A, the abundance of ZIKV E protein was higher in cells with efficient TRIM56 knockdown (shT56) than in cells bearing a nontargeting, scrambled control shRNA (shCtrl) (compare lanes 4 vs 3, and lanes 6 vs 5). Moreover, shT56 cells consistently yielded~1-log more progeny virus than did shCtrl cells, when infected at two different MOIs (Fig 3B) . These data establish TRIM56 as a restriction factor of ZIKV when expressed at physiologically relevant levels.