FIG. 4.

CypA incorporation into HIV-1 virions. 293T cells were cotransfected with plasmids encoding the wild-type (wt) or mutant HIV-1 Gag/Pol proteins and with a plasmid encoding a FLAG-tagged CypA (CypA-FLAG) protein. In the mock experiment, no viral or CypA-FLAG DNA was transfected. After 48 h, the transfected cells were lysed, and equal amounts of the total cellular proteins were subjected to Western blot analysis; the CypA-FLAG protein was detected with an HRP-conjugated anti-FLAG antibody (upper panel). Virions were concentrated from the supernatant of the transfected 293T cells by pelleting through a 20% sucrose cushion. Solubilized virion pellets were analyzed by Western blotting; the blots were probed with an HRP-conjugated anti-FLAG antibody (middle panel) and a monoclonal anti-HIV-1 p24 antibody (lower panel).