Fig. 3: Extracellular existence of Vap33 MSP domain on the plasma membrane was demonstrated by immunoelectron microscopy analysis.

a, b S2 cells stably expressing FLAG-Vap33^WT-HA were stained with anti-FLAG antibody and FluoroNanogold-conjugated secondary antibody. Stained cells were analyzed by immunoelectron microscopy. The ER (a) and the cell surface (b) are shown. Arrows in (a) indicate localization of the gold particles at the cytosolic face of the ER membrane, and those in (b) indicate localization of the gold particles at the extracellular face of the plasma membrane. Insets represent the boxed area of the right panel. Scale bars are 200 nm. Schematic representations of the microscopic images are shown. Graphs indicate the count and area (nm²) of Gold particles. The results were reproduced in 6 biologically independent experiments for a, and 49 biologically independent experiments for b. Source data are provided as a Source Data file.