Expression of wild-type or mutant PC-2 does not affect proliferation or STAT-1/p21/Cdk2 activity in HEK293 cells. (A) Whole cell lysates containing equal amounts of protein from three stable individual clones of each transfectant (Vector-only, HA-WT PKD2 and HA-R742X PKD2) were analyzed by Western blotting for expression of p21, phosphorylated STAT-1, PCNA, β-tubulin, HA and PC-2. (B) Cdk2 immunoprecipitates from two clones of each transfectant were subjected into an in vitro Cdk2 kinase assay using Histone 1A as substrate. Equal amount of Cdk2 was confirmed by immunoblotting the precipitates with anti-Cdk2 antibody. Data are representative of five independent experiments.