A. Representative time-lapse spinning disk confocal images of n = 3 of live COS7 cells stably expressing ER marker GFP-TMD (green). The cells were loaded with SiR-lysosome to visualize LE/Lys (orange). Zoom insets show a merge of the ER (GFP-TMD) (green) and SiR-lysosome labelled LE/Lys (orange). Zoom insets show a region of interest containing a mobile endosome as denoted by the white arrow. Scale bars: full size 10µm, zoom inset 3µm. Images related to movie EV1. B. Kymograph of the representative image in panel (A). 