Figure 3.

Stub1 mediates the ubiquitination and degradation of Foxp3 during stimulation with cimetidine. A. Stub1 is needed for CIM-induced reduction of Foxp3. ShStub1-HA-Foxp3 Jurkat T cells and ShCK-HA-Foxp3 Jurkat T cells were stimulated with CIM (5 μg/ml) for the indicated time period. Cell lysates were normalized for protein content and subjected to Western Blotting. The expression relative to β-actin was analyzed as intensity ratio by Image-Pro Plus: HA/β-actin (B) and Stub1/β-actin (C). Depicted are the representative results of at least 3 independent experiments. Data are expressed as means with SD from 3 independent experiments. Statistical significance was calculated using t-test (**P< 0.01 and *P < 0.05).