Subcellular distribution of wild-type and mutant tyrosinase in human melanocytes grown at 37°C. Subcellular distribution of wild-type and mutant (p.Pro21Leu, p.Cys35Arg and p.Tyr411His) tyrosinase proteins (green) in transiently transfected human melanocytes grown at 37°C. Calregulin and EEA1 were used as markers for the endoplasmic reticulum (red) and the early endosome (red), respectively. For each construct, boxed regions were magnified in the adjacent panels. Merged images show the co-localization of the p.Pro21Leu, p.Cys35Arg and p.Tyr411His tyrosinase mutations with calregulin, which indicates ER retention. The scale bar represents 10 μm for all panels.