Figure 4. The ability of linker mutants to rescue evoked synaptic transmission exhibits periodicity.

(a) Representative evoked EPSCs recorded from WT, syt KO and syt KO neurons expressing WT or proline linker mutant forms of syt. Black arrows indicate depolarization. (b) Peak amplitudes of evoked EPSCs are plotted. The 6Pro, 9Pro and 12Pro mutants fully rescued the peak amplitude; all other mutants yielded only partial rescue. The degree of rescue was well fitted by a sine wave function with a periodicity of three; an adjusted (Adj.) R² value was generated to assess the goodness of the fit. Mean values±s.e.m. are plotted. For each condition, data were collected from 21 to 33 cells from a total of six coverslips, where two coverslips were obtained from each of three independent litters of mice. Recording were made from 3 to 7 cells per coverslip. **P<0.001, ***P<0.001 versus WT, one-way analysis of variance (ANOVA) followed by Tukey's multiple comparisons test. The number of independent litters, N, and the number of cells, n, are indicated in the bar graph as N/n. Full results of the one-way ANOVA are in Supplementary Table 4.