Fig. 6. S10A synapsin does not inhibit general endocytic trafficking. (A) Surface transferrin receptor content in basal (white) or insulinstimulated (black) cells. L1 adipocytes differentiated, infected and treated with insulin as described in Fig. 6 were labeled with PE-antitransferrin receptor antibody at 4°C and mean fluorescence intensity (MFI) determined by flow cytometry. Average MFI ± s.d. of samples from four experiments, standardized to G4 basal. (B) Infected fibroblasts were labeled for 5 minutes (surface Glut4, white) or 120 minutes (total cycling pool, grey) with anti-HA antibody at 37°C, fixed, permeabilized and anti-HA detected with Cy3-labeled secondary antibody. Samples were analyzed by wide-field microscopy. MFRs were calculated for 18 fields of cells (six fields per experiment, three experiments, 20-50 cells/field). Average MFRs ± s.d., expressed as % total cycling HA-Glut4.