Fig. 6

D570Y mutation reduces the synaptic distribution of CTTNBP2 and impairs dendritic spine formation in Cttnbp2 knockdown neurons. a D570Y (DY) mutation impairs synaptic targeting of CTTNBP2. Expression pattern of WT and D570Y mutant protein in Cttnbp2 knockdown (BP2-miR) and control (Ctrl-miR) hippocampal neurons. Representative images of dendrites and enlarged spines are shown. b Overexpression of D570Y mutant protein cannot rescue the density of dendritic spines in miR-BP2 neurons. (c)–(d) Reduced Myc-D570Y signal at the tips of dendritic spines. The results of line scanning to measure the distribution of Myc-tagged WT and D570Y mutant proteins from the tip to the base of dendritic spines in Ctrl-miR- c and BP2-miR-expressing (d) neurons. Left: average intensity along dendritic spines. Right: sums of the signal between 0 and 0.5 or 1 and 1.5 μm from spine tip (shaded in grey in left panels) of each neuron. Data represent mean ± SEM. Each dot in (b, c, d) indicates the individual result of a neuron. All results were randomly collected in a blind fashion from three independent experiments. Data in (b) were analyzed by two-way ANOVA with Bonferroni’s multiple comparisons test. Data in (c) and (d) were analyzed with a Mann–Whitney test. All statistical data and exact sample sizes are available in Additional file 2: Table S1, Additional file 3: Table S2. *P < 0.05; **P < 0.01; ***P < 0.001; ns, not significant. Scale bar: a left, 10 μm; right, 1 μm