C. Representative time-lapse spinning disk confocal images of n = 3 of live COS7 cells stably expressing GFP-TMD (green) marked ER and SiR-lysosome-stained LE/Lys (orange) . Zoom insets highlight regions of interest containing a mobile endosome as denoted by the white arrow. First row represents ER (GFP-TMD) (green), the second row shows MDA generated ER movement (magenta), third row shows a merge of the two preceding channels and the fourth row shows a merge of ER (green) and LE/Lys (orange). Samples were treated with either DMSO or 2µm paclitaxel. Scale bar: 30µm and zoom insets 3µm. All images acquired for 90 frames at 1Hz.Images related to movie EV7 and 8 D. Kymograph of panel (C). E. MDA quantification of panel (C) normalized to control cells, showing the average ER movement surrounding LE/Lys under control or treated conditions and the overall average ER mobility under control or treatment conditions. Graph represents mean ±s.d. of analyses at multiple locations within the same cell (n = 20 cells per condition from 3 independent experiments). Significance two-tailed student t-test **** P<0.0001; ns = not significant. 