Fig. 3.

USP27 promotes Cyclin E abundance. a, b 293T cells were transfected with indicated plasmids and two days later were treated with 10 mg/ml cycloheximide (CHX) for 2 h and harvested. The expression of Cyclin E, USP27, and GAPDH were analyzed by western blotting a and quantified b. c The mRNA levels of Cyclin E and USP27 were determined by real-time PCR. The error bar represents the SEM of triplicate experiments. d, e Cyclin E protein stability was examined by cotransfection of USP27 or its mutant and quantified. f, g Hep3B cells were transfected with control shRNA or with shRNA specifically against USP27. Cyclin E stability was analyzed f and quantified g. h, i USP27 knockdown or control plasmids were transfected into Hep3B cells and cell were treated with the proteasome inhibitor MG132 2 h before collecting. The expression of Cyclin E and USP27 were determined and quantified