Fig. 7: Synapsin 2a mobility is sensitive to the protein’s ability to tetramerize.

a, b Representative trajectory maps (colour coded by their instantaneous diffusion coefficients; colour bar represents Log₁₀ [µm²s^-1]) of mEos3.1-tagged (a) wild-type (WT) Synapsin 2a (Syn2a^WT-mEos3.1) and (b) tetramerization deficient Synapsin 2a K337Q (Syn2a^K337Q-mEos3.1) in Synapsin triple knockout (SynTKO) hippocampal neurons. The insets are low-resolution TIRF images of the respective unstimulated presynaptic (white arrow) and axonal segments (green arrows) prior to photoconversion of mEos3.1, shown at a higher magnification. c, e Average mean square displacement (MSD; µm²) of Syn2a^WT-mEos3.1 (cyan) and Syn2a^K337Q-mEos3.1 (magenta) within (c) presynapses and (e) axons. d, f Area under the MSD curve (AUC; µm²s) for (d) presynapses and (f) axons. Data are displayed as mean ± SEM. Values were obtained from n  =  15 Syn2a^WT-mEos3.1 transfected presynapses and n = 13 Syn2a^K337Q-mEos3.1 transfected presynapses in (c, d) and from n  =  13 Syn2a^WT-mEos3.1 transfected axons and n = 18 Syn2a^K337Q-mEos3.1 transfected axons in (e, f). Data were obtained from 3 biological replicates. Statistical comparisons were performed using the unpaired two-tailed Student’s t test in (d) and (f). Source data are provided as a Source Data file.