Fig. 3

Overexpression of Kpnβ1 results in a delay in cell cycle progression. a Protein was harvested from HeLa and CaSki EGFP and Kpnβ1-EGFP cells and cell cycle markers investigated by western blot analysis. Cyclin A, cyclin D1 and pHistoneH3 were all expressed at slightly higher levels in the overexpressing cells compared to the EGFP control cells. GAPDH was used to control for protein loading. b Flow cytometric analysis of HeLa EGFP and HeLa Kpnβ1-EGFP cells following synchronization into late G1 and release into S phase. Cells were synchronized with 2 mM thymidine, harvested at various time points post release and examined by FACS analysis. An asynchronous culture of cells (async) was used for comparison. c and d Line graphs represent quantification of the percentage of cells in each phase of the cell cycle for EGFP (b) and Kpnβ1-EGFP (c) cells. Arrows represent the approximate point where 50% cells had exited the G1 phase. Results shown represent the mean ± SD. e Western blot analysis was used to determine the expression levels of cell cycle associated proteins at various time points post release following thymidine synchronization, in HeLa EGFP and Kpnβ1-EGFP cells. Protein harvested from an asynchronous culture of cells (a) is shown for comparison. GAPDH was used as a control for loading