Protein extraction, Western blotting, and total protein analysis Total protein was extracted as previously described [24] and equal volumes of cell lysates were separated on 4-15% Criterion TM TGX TM precast polyacrylamide gels (Bio-Rad, Hercules, CA). Proteins were transferred to PVDF membrane and expression of target proteins was detected with the following antibodies and dilutions: rabbit anti-BMV 1a at 1:10,000, mouse anti-BMV 2a Pol at 1:3,000, and mouse anti-Pgk1p (Molecular Probes, Carlsbad, CA) at 1:10,000 using HRP-conjugated secondary antibodies (Thermo Scientific, Rockford, IL) and Supersignal West Femto substrate (Thermo Scientific, Rockford, IL).