FIG. 2.
Accumulation of cyclin B1 in HCMV-infected cells is controlled at the levels of synthesis and degradation. (A) G0-arrested HFF cells were released from confluence by replating at a lower density. Cells were infected with HCMV Towne at an MOI of 5 (V) or were mock infected with conditioned medium (M) at the time of replating. Cells were harvested at the time points indicated and samples were processed for Western blotting for cyclin B1. Equivalent cell numbers were loaded in all lanes. Panels shown represent two independent experiments. As a loading control, lanes containing equivalent cell numbers were probed with an antibody against β-actin. (B) G0-synchronized HFF cells were infected as described for panel A. Three hours prior to harvesting, cells were treated with the proteasome inhibitor MG132 at the concentrations indicated. Cells were harvested at 18 and 21 h p.i., and the samples were processed for Western blotting with antibodies against cyclin B1. Lanes contain equivalent cell numbers.