FIGURE 7.
Effects of ITCH and SMURF-1 on the infectivity and release of HTLV-1 APPY/K74R. 3 × 105 293T cells were transfected 0.2 μg of pCMVHT-1-MΔenv-APPY or APPY/K74R, 0.3 μg of pCRU5inGlucβ, 0.03 μg of pCMV-VSV-G and the amounts of plasmids encoding FLAG-tagged-ITCH or -SMURF-1 constructs indicated in the infectivity plot in B. Representative results from one of three experiments are shown. A, overexpression of ITCH and SMURF-1 rescues the release of HTLV-1 APPY/K74R. Immunoblots of cell and pelleted VLP lysates were reacted with the indicated antisera. B, Lys-74 is necessary for complete rescue of HTLV-1. The infectivity of VLPs was determined by measuring Gluc activity in the supernatant 48 h after transfection. The infectivity of HTLV-1 APPY achieved in a co-transfection with 1 μg of ITCH was set as 100%. MA, monoclonal antibody.