Figure 5. Downregulation of the p27^Kip1 protein following PKC_α activation. A: Western blot analysis of RPE cells treated 24 h with 100 nM PMA and 100 nM thymeleatoxin reveals a strong downregulation of the p27 protein at the 1 h and 3 h time points. Gels show representative results of four independent experiments. Each well was loaded with 40 µg of protein. B: Optical density of P27 protein determined by densitometric imaging is shown (Mean±SD, n=4). The β-actin band with 42 kDa is used for quantitation.