Figure 1

Antiviral activity of the ZAP mutants. (A) The Rat 2 cells expressing the indicated NZAP-Zeo-myc mutants were challenged with MLV-luc. At 48 h post infection the cells were lysed, and luciferase activity was measured. Fold inhibition was calculated as the luciferase activity in the control cells divided by that in the NZAP-Zeo-myc expressing cells (upper panel). The expression of the mutant proteins was analyzed by Western blotting (lower panel). The fold inhibition data are mean + SD of three independent experiments. (B) Schematic representation of the mutation positions in the mutants with reduced antiviral activity. The zinc-finger domains are represented as shaded boxes. (C) The Rat2 cells expressing the indicated NZAP-Zeo-myc mutants were infected with SINV for 1 h. At 48 h post infection, the supernatants were collected and the virus was titrated. EV: empty vector-transduced cells; WT: wild-type NZAP-Zeo transduced cells. (D) 293TRex cells stably expressing the ZAP mutants in a tetracycline-inducible manner were infected with MLV-luc. At 6 h post infection, the cells were equally divided into two dishes, with one mock treated and the other treated with tetracycline. At 48 h post infection the cells were lysed and luciferase activity was measured. Fold inhibition was calculated as the luciferase activity in the mock-treated control cells divided by that in the ZAP-expressing cells (upper panel). The tetracycline induced protein expression was confirmed by Western blotting (lower panel). The fold inhibition data are mean + SD of three independent experiments.