FIG. 3.
Relative fusion activity of MSD mutants in MAGI cell assay. Fusion activity of the WT and MSD mutants was expressed using a fusion index (fusion index = 2x + y, where x is the number of multinucleated cells [number of nuclei ≥ 5 in five visual fields] and y is the number of multinucleated cells [number of nuclei < 5 in five visual fields]). The fusion index was defined to reflect the number of nuclei in multinucleated cells. Fusion activities for each mutant are shown after normalization to that of the WT (the WT activity was set at 100%). Similar results were obtained in three independent experiments.