Figure 7.

DOC2B^D218,220N and DOC2B^wt change the kinetics parameters of single-vesicle fusion. A, Representative unfiltered spike with its analysis parameters. Inset, Expansion of the first 20 ms of the spike illustrating the exponential fit of the foot and the linear fit of the rising phase. B–G, Comparison of single-spike parameters of DOC2B^wt (white; n = 16), DOC2B^D218,220N (gray; n = 24), and EGFP control (black; n = 18) cells. Error bars represent mean ± SEM. *p < 0.01; ^×p < 0.05. B, The charge of both DOC2B isoforms is increased compared with controls (p < 0.01). C, The rise time of the spike (the time of the linear phase) is longer in both DOC2B^wt- and DOC2B^D218,220N-expressing cells (p < 0.01). D, E, The duration (D) and half-width (E) of the spikes are longer in both DOC2B isoforms, although more significantly in DOC2B^D218,220N (p < 0.01) than in DOC2B^wt (p < 0.05). F, DOC2B^wt has more spikes compared with DOC2B^D218,220N and EGFP control cells (p < 0.05). G, DOC2B^D218,220N has more feet than DOC2B^wt and EGFP control cells (p < 0.05).