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 corroborate this finding, we evaluated ZIKV propagation efficiency in HEK293 cells stably transduced with an empty retroviral vector (Bsr), WT or TRIM56 mutants (AA and Mut N), respectively. Compared with that in Bsr control cells, ZIKV E protein abundance was reduced in cells overexpressing WT TRIM56 (Fig 4C, compare lanes 6 vs 5) but not in cells overexpressing either TRIM56 mutant (Fig 4C, compare lanes 7 and 8 vs 5) . The AA and Cterminal aa 693-750 deletion mutants also lost their abilities to limit progeny ZIKV production, as compared with WT TRIM56 (Fig 4D, compare bars 3 and 4 vs 2, increases of~12-19-fold). In aggregate, these results suggest that the E3 Ub ligase activity and the C-terminal 693-750aa portion are both indispensable for TRIM56-mediated restriction of ZIKV.