FIG. 5.

Viral protein synthesis in cells infected by viJ1R. (A) Pulse-labeling of viral proteins. BSC40 cells were infected with vT7lacOI or viJ1R at an MOI of 10 PFU per cell in the presence (+) or absence (−) of 50 μM IPTG. The cells were labeled with [³⁵S]methionine (50 μCi/ml) for 15 min at 1, 2, 4, 6, 8, 12, and 24 h p.i. m, mock infected. Immediately after labeling, the cells were washed and lysed, and the labeled proteins were separated by SDS-10% PAGE. (B) Pulse-chase analysis of precursor p4a and p4b processing. BSC40 cells were infected with either vT7lacOI or viJ1R in the presence (+) or absence (−) of 50 μM IPTG. At 8 h p.i., the cells were pulse-labeled with [³⁵S]methionine for 30 min and either immediately harvested (−) or chased with normal medium for 0.25, 0.5, 1, 2, 4, 12, or 24 h. Proteins were denatured and analyzed by SDS-10% PAGE followed by autoradiography. The mobilities of p4a and p4b and their mature processed forms, 4a and 4b, are shown at the left (68, 69).