FIG 2.

HSP90 activity is required for efficient genome replication of RUBV and SINV. (A) Vero cells were infected with RUBV for 1 h. After washing, the cells were cultured for 18 h (incubation phase) with NH₄Cl. Then, the cells were cultured in the presence or absence of 2.5 μM 17-AAG for 30 h (evaluation phase) with 20 mM NH₄Cl to block the secondary infections. The viral genomic RNA and the host HPRT1 mRNA were quantified by real-time RT-PCR at the indicated time points. The graph shows the viral genomic RNA copy numbers relative to those of HPRT1 mRNA. (B) Vero cells were infected with SINV for 1 h. After washing, the cells were cultured for 4 h (incubation phase). Then, the cells were cultured in the presence or absence of 2.5 μM 17-AAG for 14 h (evaluation phase). NH₄Cl (20 mM) was used to block secondary infections. The viral RNA and the host HPRT1 mRNA were quantified by real-time RT-PCR at the indicated time points. The graph shows the viral RNA copy numbers relative to those of HPRT1 mRNA. (A, B) Data are representative of those from three independent experiments. Mean values ± SD for four wells are shown. The significant differences were determined by two-tailed t tests. **, P < 0.01.