Figure 3. HER2-Akt signaling reduces CSN6 turnover via decreasing CSN6 ubiquitination. (A) CSN6 turnover rate is decreased in HER2-overexpressing cells. Indicated cells were treated with cycloheximide (CHX) (100 µg/ml) for the indicated times. Cell lysates were immunoblotted with indicated antibodies. (B) Akt dereases the turnover of CSN6. Indicated 293T cells were transfected with GFP-CSN6 with or without Akt and then treated with cycloheximide (CHX) (100 µg/ml) for the indicated times. (C) CSN6 turnover rate is increased in Akt activity deficient cells. Indicated cells were treated with cycloheximide (CHX) (100 µg/ml) for the indicated times. Cell lysates were immunoblotted with indicated antibodies. (D) Akt stabilizes CSN6 by decreasing CSN6 ubiquitination. 293T cells were transfected with the indicated plasmids. The proteasome inhibitor MG132 was added 6 h before harvesting cells. The ubiquitinated amount of CSN6 is analyzed by immunoprecipitated (IP) with anti-GFP followed by immunoblotting (IB) with anti-ubi.