Although PRWKz and PRKWz showed cellular Gag processing profiles similar to those of PRKz and PRKKz at 48 h, they displayed higher p24 gag /Pr55 gag ratios compared to Gag/PR at 24 h post-transfection ( Fig. 2B upper panel, lanes 15-16 vs. lane 10) . This suggests that LZ domain placement significantly enhanced Gag processing efficiency. The virus-associated Gag precursor that we detected may reflect, at least in part, the release of assembled Gag molecules that escaped PR-mediated cleavage (Fig. 2B, lanes 7-8) .