FIG. 2.
The level of P protein is crucial for growth of RV in IFN-competent cells. (A) Genome organization of recombinant RV. SAD PLP carries an extra copy of the P gene downstream of L (gene order, 3′-N-P-M-G-L-P-5′). In SAD ΔPLP, the P gene downstream of N in SAD PLP was deleted, resulting in a virus with a single P gene copy downstream of L (gene order, 3′-N-M-G-L-P-5′). (B) Northern blot hybridization with N and P gene-specific cDNA of RNA from BSR T7/5 cells infected for 24 h at an MOI of 1 with the indicated viruses. SAD ΔPLP virus produces lower levels of P mRNA than SAD L16. (C) Expression of RV N, P, M, and G proteins was analyzed in Western blots of cell extracts from BSR T7/5 at 24 h p.i. at an MOI of 1. (D and E) Single-step growth curves were performed on BSR T7/5 cells (D) and on HEp-2 cells (E) after infection with the indicated viruses at an MOI of 0.01. ffu, focus-forming units.