(C) Exemplary TEM image of a WT cell incubated with OA for 1h. A grid is randomly placed on top of the image and the width of perpendicularly oriented ER profiles passing through grid lines are measured. Yellow lines indicate measured sites. (D) ER profile analysis of (C). Bars: average profile width/cell, ± SEM, n= 11-9 cells (149-224 profiles), *p<0.05 (unpaired T-test). 