(c) Mutation of the C2 domain leaves UVRAG unable to associate with the ER. HeLa cells expressing Flag-UVRAG (WT) or its K78A/R82A mutant were fixed and processed for confocal microscopy for co-localization with the ER marker PDI (top panel). Insets highlight the relative distribution of UVRAG at the ER. UVRAG and endogenous PDI expression were confirmed by immunoblotting (bottom panel). See Supplementary Fig. S9 for uncropped data. Scale bars, 10 μm. 