FIGURE 6.

The 3′ UTR and poly(A) tail function as individual elements to stimulate IRES-mediated translation. (A) The in vitro transcribed products of plasmid pDHAV-3′UTR-ΔA₂₅ or pDHAV-Δ3′UTR-A₂₅ were transfected into DEFs, and reporter RNAs of pDHAV-3′UTR-A₂₅ or pDHAV-Δ3′UTR-ΔA₂₅ were used as positive or negative controls, respectively. The stimulation values between 3′ UTR-containing RNAs and poly(A)-containing RNAs were compared. 0.1 μg of pGMLR-TK plasmid was co-transfected with reporter RNAs, and the RLuc activity was measured at each detection point. Bars represent the means ± standard deviations of three replicate experiments. ^∗∗∗P < 0.001, ^∗∗P < 0.01. (B) After transfection of pR-DHAV-1-3′UTR-ΔA₂₅ or pR-DHAV-1-Δ3′UTR-A₂₅ into DEFs, cell lysates were collected at 4 hpt and used for western blot analysis, with pR-DHAV-1 and pR-DHAV-1-Δ3′UTR-ΔA₂₅ used as controls. The anti-DHAV-1 monoclonal antibody 4F8 (dilution: 1:500) and HRP-labeled goat anti-mouse antibody (dilution: 1:3000) were used for western blot analysis.