Figure 4.

Doc2α and β are direct Ca²⁺-sensors driving spontaneous glutamate and GABA release. A. The indicated Doc2α constructs were expressed in Doc2α KO neurons using lentivirus. B. Representative traces (left) and quantification (right) of recordings in Doc2α KO neurons expressing a control (GFP), Doc2α WT, or Doc2α D291N. An ANOVA test comparing the rates for all constructs was significant with p < 0.001, graphical comparisons represent pairwise post-hoc tests. C. Doc2β constructs were expressed in Doc2β KO neurons using lentivirus. D. Representative traces (left) and quantification (right) of recordings in Doc2β KO neurons expressing a control (GFP), Doc2β-WT, or a mutant construct of Doc2β. An ANOVA test comparing the rates for all constructs was significant with p < 0.001, graphical comparisons represent pairwise post-hoc tests. E. Quantification (left) and traces (right) of mIPSC recordings made in the absence of Ca²⁺ in Doc2β KO neurons rescued with either Doc2β WT or Doc2β 6x. Remarkably, expression of Doc2β 6x mutant allowed significant miniature release to occur in the absence of Ca²⁺. * denotes p < 0.05, ** denotes p < 0.01, *** denotes p < 0.001, n.s. denotes p > 0.05. Bar graphs represent mean ± SEM. See also Supp. Fig. 4.