Figure 12.

Oct-1 is required for optimal KSHV reactivation. A, Oct-1 is induced during KSHV reactivation in PEL cells. KSHV-infected BC-3 cells were treated with TPA or with vehicle control (mock) and tested for Oct-1 expression by Western blotting. Purified recombinant GST–Oct-1 protein was included as a Western blotting control. Numbers at left indicate positions of protein apparent molecular weight standards. B, Oct-1 siRNA specifically knocks down Oct-1. Whole-cell protein extracts from Vero cells transfected in Fig. 10A were pooled, and equal concentrations were analyzed by SDS-PAGE/Western blotting. RRL = rabbit reticulocyte lysate programmed to express Oct-1 protein. The asterisk indicates migration of Oct-1–specific protein band. Numbers at left indicate positions of protein apparent molecular weight standards. C,. Oct-1 knockdown debilitates KSHV reactivation. KSHV-infected Vero rKSHV.294 cells were transfected with Oct-1–specific siRNA and control siRNA (scrambled), incubated for 48 h, and then treated with 1.0 mm VPA for 6 h. Media were replaced with fresh media and incubated an additional 48 h. Infectious virus was quantitated by SeAP assay. Fold reactivation was calculated by normalizing SeAP activity to that for control cells, which had been incubated with supernatants from Vero rKSHV.294 cells that were transfected with control siRNA without VPA. Thick lines indicate means of values, and thin lines indicate standard errors. Nontarg = transfected with control (nontargeting) siRNAs.