FIG. 5.

Pulse-chase analysis of a subset of SINV mutants. BHK cells were electroporated with 10 μg of in vitro-transcribed RNA and incubated at 37°C. At 6 h postelectroporation, the cells were starved for methionine and treated with actinomycin D to a final concentration of 1 μg/ml. At 6.5 h postelectroporation, the cells were pulsed with [³⁵S]methionine (50 μCi/ml) for 15 min. The samples were then washed with MEM–100× methionine and overlaid with MEM containing 5% dialyzed fetal bovine serum and 10× methionine. The cells were incubated for an additional 30 or 60 min at 37°C, at which time cytoplasmic extracts were prepared and examined by SDS-PAGE followed by autoradiography.