Figure 6.

RNAi directed against members of the eIF3 protein complex does not affect Cyclin E expression but does affect Cyclin E-associated kinase activity. (A) Western blot for Cyclin E expression in whole cell extracts from S2R+ cells treated with the indicated dsRNAs. (B) Kinase activity on histone H1 of Cyclin E immunoprecipitates from S2R+ cells treated with the indicated dsRNAs. (C) Kinase activity on histone H1 of Cyclin E immunoprecipitates from S2R+ cells treated with dsRNA targeting the indicated members of the COP9 signalosome, proteasome lid or eIF3 protein complex in combination with either dsRNA targeting GFP or Dacapo.