FIG. 6.

Hsc70 maintains cyclin D1-dependent cell cycle progression in the presence of inhibitory levels of p21^Cip1. (A) NIH 3T3 cells were transfected with vectors encoding Flag-D1 and CDK4, Flag-D1, CDK4, and p21^Cip1, or Flag-D1, CDK4, p21^Cip1, and Hsc70; 24 h posttransfection, cells were labeled with bromodeoxyuridine (BrdU) for 20 h. Cells were fixed and stained with monoclonal M2 antibody (red), bromodeoxyuridine (green), and Hoechst dye (blue). (B) Quantitation of panel A, representing three independent experiments; error bars represent standard errors between experiments. (C) Whole-cell lysates prepared from cells transfected as for panel A were resolved by SDS-PAGE, and levels of p21^Cip1 were monitored by immunoblot analysis with a p21-specific antibody.