Figure 1.

Schematic diagrams of membrane protein–GFP fusion proteins used in this study. GAP-43 and SNAP-25 do not contain transmembrane domain, but are associated with the plasma membrane by lipid moiety at their NH₂-terminal and central regions, respectively. Synaptophysin has four transmembrane domains and its COOH-terminal region is located on the cytoplasmic side of the synaptic vesicles. TrkA and TGN-38 contain one transmembrane domain and their COOH-terminal regions are located on the cytoplasmic side of the plasma membrane and the TGN. GFPs were fused with the COOH-terminal region of these membrane proteins, and thus located on the cytoplasmic sides.