FIG 1.

Riplet augments ZAP-mediated restriction of HIV-1 reporter virus. (A) Schematic representation of two major isoforms of ZAP. ZAP-L, the long form; ZAP-S, the short form. Zinc fingers, WWE domain, and PARP-like domain are indicated. (B) Schematic representation of the domains of Riplet and mutant constructs. RING, coil domain, and PRY/SPRY domain are indicated. (C) Riplet overexpression augments ZAP-mediated restriction of retroviral infection. 293TrexhZAP cell lines expressing the indicated DNAs were infected with VSVG-pseudotyped HIV-luc reporter virus followed by ZAP induction with doxycycline or DMSO as a control at 6 h postinfection. Firefly luciferase reporter activity was measured at 24 h postinfection and normalized to total protein content measured by a Bradford assay for each sample. Data points presented are the mean RLU/mg ± SD values of four independent experiments done in triplicate. (D) Riplet-mediated increase in ZAP-mediated HIV-1 inhibition, derived from data in panel C. 293TrexhZAP cell lines expressing the indicated DNAs were infected with VSVG-pseudotyped HIV-luc reporter virus followed by ZAP induction with doxycycline or DMSO as a control. Fold inhibition of virus was calculated as the ratio of luciferase expression levels in DMSO-treated cells to those in doxycycline-treated cells. Data points represent the mean ±SD values of four independent experiments. Student's t test was used for statistical analysis. ***, P < 0.0002; *, P < 0.02.