Fig. 7.

Impaired nuclear import of HDAC4 contributes to endplate defect in TSCmKO muscle. a–c Confocal pictures of HDAC4 (red, a), myogenin (red, b) and acetylated histone H4 (red, c) combined with α-bungarotoxin (Btx, green) in single fibers isolated from innervated and denervated (De) control (Ctrl) and TSCmKO muscles. Arrows and arrowheads show sub- and extra-synaptic (Syn) myonuclei, respectively. Representative of 4 independent muscles. Scale bar, 25 µm. d Confocal pictures of electroporated HDAC4 (red) and laminin (green) in innervated and denervated control and TSCmKO muscles. Representative of 4 independent muscles. Scale bar, 5 µm. 3D reconstruction is given in Supplementary Fig. 7d. e Confocal pictures of electroporated HDAC4 (red), α-bungarotoxin (Btx, green) and laminin (gray) on muscle section (upper panel) or in isolated fibers (bottom panel) from TSCmKO denervated muscle. Arrows point to sub-synaptic nuclei. Representative of 4 independent muscles. Scale bar, 10 µm. f, g Representative confocal pictures of “old” (green) and “new” (red) AChRs in TSCmKO denervated muscles (14d), electroporated with GFP or GFP-HDAC4 (gray). Scale bar, 50 µm. Turnover quantification is given in (g); values are mean ± s.e.m.; n = 6 GFP and 7 HDAC4 independent assays (number of mice electroporated; 136 and 50 fibers quantified, respectively); two-tailed unpaired Student’s t-test, ***p < 0.001. Source Data are provided in the Source Data File