Fig. 3.
1,25(OH)2D3 induces an initial increase followed by a rapid decrease in Cdk2- and p21-associated kinase activities in U937 cells. (A) Cdk2- or (B) p21-containing complexes were immunoprecipitated from U937 lysates at the indicated times after 1,25(OH)2D3 exposure using anti-Cdk2 or p21 antibodies, and subsequent kinase reactions were performed using GST-RB as a substrate.