FIG 4.

BBC treatment of infected cells decreases stable cytoplasmic nucleocapsids. BHK-21 cells were infected with ppSFV at an MOI of 10, treated with DMSO or BBC starting at 4 hpi, and then labeled with [³⁵S]methionine/cysteine starting at 4.5 hpi in the continued presence of DMSO or BBC. At 8.5 hpi, cells were solubilized and analyzed by sucrose density gradient sedimentation. (A) Alternating fractions were analyzed by SDS-PAGE and fluorography, where TL represents equivalent aliquots of the total cell lysates. (B) The bottom of the tube was washed with SDS sample buffer to collect any Cp-bound complexes that pelleted through the 60% sucrose cushion, and analyzed as in panel A. (C) Radioactivity in all fractions was analyzed by scintillation counting. The Cp peak from fractions 3 to 9 represents cytoplasmic nucleocapsids, and the peak from fractions 15 to 19 represents Cp bound to ribosomes. The results shown in panels A, B, and C are representative of three independent experiments.