FIGURE 2.

Overexpression of MKL2 resulted in SRF-mediated transcriptional activation and dendritic complexity. A, increased level of SRF-mediated transcription by the overexpression of MKL2. An empty vector (empty) or myc-tagged MKL2 expression vector (MKL2) (3 μg/well) was cotransfected with luciferase and β-galactosidase reporter vectors, SRE-Luc and RSV-βgal, respectively (1 μg/well), in cortical neurons. Luciferase or β-galactosidase activity was measured 48 h after transfection. The β-galactosidase reporter vector was used as an internal control. Bar graphs represent the mean ± S.D. from four samples. The same trends were obtained from at least two independent experiments. **, p < 0.01 versus control. B–D, MKL2 overexpression modulation of dendritic morphology. B, immunofluorescent images of cortical neurons expressing GFP (2 μg/well) and either the empty vector (empty: left panel, 2 μg/well) or the myc-tagged MKL2 construct (MKL2: right panel, 2 μg/well). Cells were fixed 48 h after transfection. Cells expressing GFP were MAP2-positive (supplemental Fig. S1A). C and D, dendritic complexity analyzed in the experimental conditions shown in B. Graphs represent the mean ± S.D. from four independent experiments. C, Sholl analysis. *, p < 0.05 versus control; **, p < 0.01 versus control. D, dendritic length. **, p < 0.01 versus control.