FIG 4.

The 5′ UTR of DTMUV lacks substantial IRES activity. (A) Schematic presentation of bicistronic reporters. The diagrams are not to scale, and the poly(A) tails of Dual-IRES-3EMCV and Dual-ΔIRES-3EMCV are not shown. (B) BHK-21 cells transfected with uncapped bicistronic reporters were lysed at 4 h p.t., and RLuc and FLuc activities were measured. (Left) Translation of the upstream cistron (RLuc). (Right) Translation of the downstream cistron (FLuc). The RLuc and FLuc activities are presented as means plus SD (n = 3). (C) BHK-21 cells were transfected with capped/uncapped DTMUV-RLuc or SL-DTMUV-RLuc, and RLuc activities were measured at 4 h p.t. (C) BHK-21 cells transfected with capped/uncapped DTMUV-RLuc or SL-DTMUV-RLuc were lysed at 4 h p.t., and RLuc activities were measured.