Figure 6.
Effects of p53 siRNA on cell cycle regulatory proteins. (A) Vector and p53 siRNA transfected cells were treated with 10 μM of polyamine analogue for 96 h and subjected to immunoblotting with an antibody to p21, cyclin D1 or cyclin B1. Actin protein was blotted as a control. Each experiment was performed twice with similar results. (B) CDKs complexes were immunoprecipitated with anti-CDKs antibody and then subjected to an in vitro kinase assay (KA) using pRb as the substrate. CDK protein expression was analyzed by Western blotting as a control (IB).