FIG. 2.

Cytoplasmic expression of p21 depends on NLS in monocytic differentiation. GFP signals in cells transfected with GFP-tagged p21-NLS constructs are shown. WEHI3B D+ cells were transfected with a construct containing GFP fused with p21 (aa 80 to 164). GFP-positive cells were selected and cultured with 50 ng of TPA/ml and 50 nM VD₃ and then examined by confocal microscopy. Photos in the left and right columns show transfected cells before and after culture with TPA plus VD₃, respectively. Monocytic differentiation induction resulted in the cytoplasmic expression of GFP signal in cells transfected with p21-NLS. TPA plus VD₃ induced no difference of GFP signal in cells transfected with the p21 construct without NLS. Top, middle, and bottom panels show GFP signals, nuclear staining with Hoechst 33258, and a phase-contrast view of the corresponding fields, respectively.