Fig. 9. Interactions of cell cycle regulators in control and differentiating A.1 and 1.3 EC cells. EC cells were cultured for 48 h with and without 10-6 M RA, and then proteins were extracted. Immunoprecipitation reactions were carried out using the equal amounts of total protein and the appropriate antibodies. Immunoprecipitates (IP) were electrophoresed on 10% SDS-PAGE and Western blotted using primary antibody against the appropriate associating partner. Data are representative of at least three independent replicates. A, p27 and CDK4. B, CDK2.