FIG. 1.

4×CTE-dependent RNA nuclear export and deletion of the MA globular head both increase VLP production in murine cells. (A) Depiction of cytomegalovirus major immediate-early-driven surrogate gRNA transcripts carrying either RRE or 4×CTE nuclear export elements and encoding either wild-type (WT) Gag (GP) or Gag carrying a deletion of the MA globular-head domain (Δ8-126). (B) 3T3 (lanes 1 to 4) or HeLa (lanes 5 to 8) cells were cotransfected with 1 μg or 250 ng (25%), respectively, Gag expression plasmids encoding the indicated transcripts plus plasmids encoding either Rev or luciferase (Luc) as indicated. Cell lysates and VLPs were collected 48 h posttransfection, resolved by SDS-PAGE, and immunoblotted for Gag and HSP90 (loading control).