Figure 2
From: The prototype foamy virus protease is active independently of the integrase domain
In vivo cell culture PR-activity assays and deletion of integrase domain in the proviral context. (A) HEK 293 T cells were cotransfected either with a codon-optimized PFV pcoPP or a pPR-RT expression plasmid, 0.5 μg of the pcoPG4 as PR substrate and the gfp-encoding pMD9 as source for viral RNA (DNA amounts are indicated in [μg]). PR activity and Pol expression was determined by Gag (upper panel) and Pol (middle panel) Western blotting analysis using monoclonal antibodies. Determination of the GAPDH concentration served as loading control (lower panel). Positions of the molecular size makers are indicated. (B) The IN is required for Pol encapsidation. Viruses isolated from cell culture supernatants and cellular lysates were analysed for Pol and Gag expression and maturation by Western blotting.