Kinetics of CHK2 and PP2A B’α dissociation after exposure to IR. 293T cells were transiently transfected with FLAG-B’α and (A) irradiated with 2, 5, 10, 20 or 50 Gy and incubated for 1 h, (B) irradiated with 20 Gy and incubated for 0.5, 1.0, 1.5, 2.0 or 2.5 h, (C) irradiated with 6 Gy and incubated for 1, 4, 8 or 12 h, and (D) irradiated with 50 Gy and incubated for 1, 4, 8 or 12 h. Whole cell lysates were immunoprecipitated with the FLAG antibody and immunoblotted for the indicated proteins.