FIG 4.

ATF4 induces ATF3 expression and promotes ZIKV protein and RNA expression. A549 WT cells stably expressing either control or ATF4 targeting shRNA were treated with tunicamycin (TU) or infected with ZIKV^PR (moi=10 PFU/cell). (A) ATF4, ATF3 and ZIKV NS1 proteins were assayed via western blot with GAPDH expression measured as the loading control. The blot shown is a representative of three separate experiments. (B-C) Fold change (2^−ΔΔCt) in ZIKV and ATF3 RNA expression relative to ACTB mRNA was determined by RT-qPCR. The RT-qPCR results presented are the mean ± SD of three technical replicates from three separate experiments. Statistical significance was determined by Student T-test. **p<0.05, ns-not significant, * non-specific band detected by the anti-NS1 antibody.