FIGURE 2.

Fbxw15 mediates HBO1 degradation. A, several SCF V5-tagged F box subunit plasmids were overexpressed in MLE cells for 48 h, and the cells were harvested prior to immunoblotting with HBO1, V5, and β-actin antibodies. B, different amounts of pcDNA3.1/Fbxw15/V5 or pcDNA3.1/Fbxw14/V5 plasmids were overexpressed in cells for 48 h. The samples were cells harvested prior to immunoblotting with HBO1, V5, and β-actin immunoblotting. C, scrambled RNA or Fbxw15 shRNA plasmids (4 μg) was transfected into cells. The cells were then treated with 20 μm of cycloheximide (CHX) for various time points prior to immunoblotting with HBO1 and β-actin antibodies. The bar graph represents steady-state levels of Fbxw15 mRNA. D, a pcDNA3.1/Fbxw15/V5 plasmid or pcDNA3.1/Fbxw17/V5 plasmid (4 μg) was transfected into cells. The transfected cells were then treated with 20 μm of CHX for various time points. The samples were subjected to HBO1, V5, and β-actin immunoblotting. In B–D, the results of densitometric analysis of immunoblots are represented graphically on the right. The data are representative of three separate experiments.