Figure 7.
Nuclear-targeting properties of the three β4 splice variants in reconstituted cerebellar granule cells from lethargic mice. Cultured CGCs from lethargic mice were reconstituted by lentiviral transfection with βA-β4a, βA-β4b, or βA-β4e and immunolabeled at DIV 4 and 9 with anti-β4. A, Wild-type and transfected neurons show similar β4 staining in the periphery of the somata. In addition, β4b and, less often, β4a show nuclear localizations at both developmental stages. Scale bar, 10 μm. B, Percentage of reconstituted cultures showing that nuclear targeting of β4b was 2.5 times higher than that of β4a and 4 times higher than that of β4e. ***p < 0.001; *p < 0.05. C, Blocking the spontaneous activity by 1 μm TTX for 12 h at DIV 9 shows a significant increase (p = 0.04) in nuclear targeting of β4b, but no effect on β4a or β4e. ***p < 0.001; *p < 0.05, ANOVA and Tukey post hoc test.