B. Representative stills of spinning disk confocal images of n = 3 of COS7 cells stably expressing TMD-GFP (green) and SiR-lysosome-stained endosomes/lysosomes (orange). COS7 cells in the middle panels overexpress mCherry-RILP (magenta). The COS7 cells in the lower panels overexpress mCherry-TMEM55B (magenta). Zoom insets show region of interest containing the ER (TMD-GFP) (green) and junction analysis of the skeletonized ER where the number of ER junctions representing the quantified average. Scale bars: 15µm. zoom insets: 3µm. C. Quantification of the number of ER junctions per µm2 from panel (B) as resulted from ER junction analysis. Graph represents mean ±s.d. of analyses at multiple locations within one cell (n=15 from 3 independent experiments). Significance two-tailed student t-test. ***P<0.001. 