Figure 2

Live cell imaging of HPS3 and acidic vesicles. (a) Lysotracker Red stained acidic vesicle trafficking in live HPS3 null fibroblasts expressing GFP-HPS3 [A] or GFP-HPS3-delCBD [B]. Cells were imaged on a 37°C warming stage following a 2 h incubation at 20°C. Lysotracker Red stained acidic vesicles and GFP-HPS3 transiently co-localized in the perinuclear area [A]. Inset shows the location of the time series shown in (b). GFP-HPS3-delCBD did not localize predominantly to the perinuclear area and showed no co-localization with Lysotracker Red [B]. (b) Time series showing co-trafficking of GFP-HPS3 and Lysotracker Red stained vesicles from the perinuclear area in HPS3 null fibroblasts. Note transient association of GFP-HPS3 with an acidic vesicle as it travels peripherally over a period of time (see [additional file 1]).