NLS1 is required for nuclear localization. (A) Colocalization of GFP, NLS1-GFP, and NLS2-GFP with the nucleus. Chromatin is stained with DAPI. Magnification, ×63. (B) Assessment of ΔNLS1 and ΔNLS2 CASZ1b cellular localization. FLAG-tagged WT CASZ1, ΔNLS1 CASZ1b, and ΔNLS2 CASZ1b are stained with an anti-FLAG antibody, and chromatin is stained with DAPI. Magnification, ×63. (C) Activation of the TH-luciferase construct by WT, ΔNLS1, and ΔNLS2 CASZ1b 24 h after transfection. Data are plotted as the means ± SDs of two independent experiments (*, P < 0.05; **, P < 0.001). (D) Western blot showing steady-state levels of WT, ΔNLS1, and ΔNLS2 CASZ1b 24 h after transfection.