Env adaptations elevate levels of Gag-Pol packaging.

(A) Immunoblot data from pseudo-single cycle assays of the indicated viruses produced in SupT11-A3G cells treated with the protease inhibitor DRV at 20 μM concentration. Immunoblots of the indicated proteins in viral particles and producer cells from one representative experiment of 3 biologically independent experiments. (B) p160 expression in SupT11-A3G cells infected with the indicated viruses. p160 expression levels were quantified by determining cellular band intensities, normalized to levels for WT virus, and then dividing by relative p55 levels (mean +/- SD of 3 biologically independent experiments). (C) p160 expression in the indicated viral particles produced from SupT11-A3G cells. p160 packaging levels were quantified by determining viral particle band intensities, normalizing to levels for WT virus, and then dividing by relative p55 levels (mean +/- SD of 3 biologically independent experiments). (D) p160/p55 ratios in viral particles relative to those in cells (values from panel C divided by those in panel B; mean +/- SD). (E) p55 to p160 ribosomal frameshift efficiency in SupT11-A3G cells infected by viruses with the indicated genotypes. p160 expression levels were quantified based on band intensity and divided by the sum of the p160 and p55 band intensities (mean +/- SD of 3 biologically independent experiments). (F) Efficiency of p160 packaging into viruses with the indicated genotypes produced in SupT11-A3G cells. p160 expression levels were quantified based on band intensity and divided by the sum of the p160 and p55 band intensities (mean +/- SD of 3 biologically independent experiments). Statistical comparisons for data in panels B-E were done using Student’s t test (p-values above each panel in comparison to data for Vif-null HIV-1).