DDB1 regulates GRK5 degradation.

<p>(A) 293 T cells were infected with lentivirus expressing control RNAi or DDB1 RNAi. Cells were treated with 100 µg/ml CHX for the indicated time. Cell lysates were analyzed by Western blotting with antibodies specific for the indicated proteins. Quantitative graphs are shown. The amount of GRK5 at 0 h was defined as 100%. Data are the mean±SE from 4 independent experiments. *p<0.01. (two-way ANOVA) compared with control RNAi. (B) 293 T cells were treated with geldanamycin at indicated concentration for 24 h at 37°C. Cell lysates were analyzed by Western blotting with antibodies specific for the indicated proteins. (C) 293 T cells were pretreated with or without 10 µM MG132 for 1 h followed by incubation with geldanamycin for 12 h. Cell lysates were analyzed as in B. (D) 293 T cells were infected by lentivirus encoding control or DDB1 RNAi. Cells were treated with 1 µM geldanamycin for the indicated time. Cell lysates were analyzed as in B.