Figure 1. RhoA degrades in the proteasome system in lung epithelial cells.

A. MLE12 cells were transfected with V5 tagged RhoA wild type (RhoA-V5), RhoA active form (RhoAV14-V5), or RhoA inactive form (RhoAN19-V5) plasmids for 48 h. Cells were treated with cycloheximide (CHX, 20 μg/ml) for indicated times and then cell lysates were analyzed for over-expressed RhoA and β-actin by immunoblotting with V5 tag and β-actin antibodies. B. RhoAV14-V5 over-expressed MLE12 cells were treated with 20 μg/ml of CHX with or without MG-132 (20 μM) or leupeptin (100 μM) for 2 h. Cell lysates were analyzed for RhoAV14-V5 and β-actin by immunoblotting with V5 tag and β-actin antibodies. C. RhoAN19-V5 over-expressed MLE12 cells were treated with 20 μg/ml of CHX with or without MG-132 (20 μM) or leupeptin (100 μM) for 2 h. Cell lysates were analyzed for RhoAN19-V5 and β-actin by immunoblotting with V5 tag and β-actin antibodies. Shown are representative blots from three independent experiments.