FIG. 7.

Effects of mutations in the LWYIK motif on the Env membrane fusion ability. 293T cells were cotransfected with pIIIextat along with the ΔKS (control), WT, or mutant pSVE7puro plasmids as indicated and cocultured with 10⁶ H938 cells, and CAT activity was assessed. A representative result is shown in panel A. The background CAT level detected in the absence of Env (control) was subtracted from the CAT activity detected in the presence of the WT or mutant proteins. The relative membrane fusion activity of the mutant proteins is expressed as a percentage of that of the WT Env. The results from three independent experiments (mean ± standard deviation) are shown in panel B.