Figure 5.

Effect of cell proliferation on subcellular localization of HDAC4. (A) HCT116 cells were transfected with HDAC4-GFP, and serum-starved for 24 h. Cells were then either maintained in 0% serum, or they were serum-pulsed (10%) for 16 h. Representative histograms after flow cytometric analysis are shown. (B) Representative fields of HDAC4-GFP 1-1084-transfected cells (green) after serum starvation, or after serum pulse. Nuclei are stained with DAPI (blue). (C) The distribution of HDAC4-GFP after serum starvation, or serum pulse was analyzed by counting 200 GFP-positive cells per treatment. The distribution was categorized as either nuclear or exclusively cytoplasmic. Values shown are mean + SEM of three independent experiments; *p < 0.05 relative to no serum, Student's t test. (D) Endogenous HDAC4, HDAC1, HDAC6, and PCNA protein levels in nuclear and cytosolic fractions were determined by Western blot after subcellular fractionation of serum-starved and serum-pulsed cells.