SNAP25 knockdown inhibits endocytosis. A, Western blot of SNAP25, clathrin, dynamin, AP2, endophilin, and actin from PC12 cells in control (left) and in cells transfected with SNAP25 shRNA (KD, right). B, Immunostaining of SypH2X (antibody against GFP, left, green) and SNAP25 (middle, red) at neuronal branches with (arrow, green staining) or without (no green staining) transfection of SypH2X and SNAP25 shRNA (right: left and middle panels superimposed). C, The SypH2X signal induced by Train10s at control boutons transfected with SypH2X (black, n = 6 experiments) or with SypH2X and scrambled shRNA (gray, n = 4). Data are expressed as the percentage change over the baseline intensity, and plotted as mean + SEM (every 10 s, applies to all similar plots). D, The SypH2X signal induced by Train10s at boutons transfected with SypH2X and SNAP25 shRNA (n = 12 experiments, SNAP25 KD). E, Traces in C (black only) and D (red) are normalized to the peak amplitude and superimposed. F, The SypH2X signal induced by Train1.5s at control boutons transfected with only SypH2X (black, n = 7 experiments) or with SypH2X and scrambled shRNA (gray, n = 7). G, Traces in F (black only) and D (red) are normalized to the same amplitude and superimposed.