C,D Summary graphs of the membrane distribution of Syx1 (C) and Munc18-1 WT or mutants (D) quantified by the ratio of fluorescence at the plasma membrane (PM) to the total fluorescence in the whole cell (total). DiD is the PM marker. Numbers of pictures analyzed are shown as follows: no Syx1, n = 14; no M18, n = 15; WT, n = 24; QKAA, n = 23; KKEE, n = 12; L348R, n = 22. 