Figure 2.

Binding between CHK2 and PP2A is dissociated by IR-induced DNA damage. (A) 293T cells transiently transfected with FLAG-B’α or empty vector (FLAG) were irradiated with 20 Gy and incubated for 1 h. Whole cell lysates were immunoprecipitated using a FLAG antibody and immunoblotted for the indicated proteins. (B) 293T cells transiently transfected with HA-tagged B’α, B’β, B’δ, B’ε or B’γ3 were irradiated with 20 Gy and incubated for 1 h. Whole cell lysates were immunoprecipitated with the HA antibody and immunoblotted for the indicated proteins. (C) 293T cells were irradiated with 20 Gy and incubated for 1 h. Whole cell lysates were immunoprecipitated with an antibody to CHK2 and immunoblotted for PP2A C. (D) 293T cells transiently transfected with FLAG-B’α were exposed to either 20 Gy IR and incubated for 1 h, 50 J/m² UV and incubated for 2 h, 2 mM hydroxyurea (HU) for 24 h, 0.5 μg/mL mitomycin C (MMC) for 24 h, or 1 mM doxorubicin (DoX) for 2 h. Whole cell lysates were immunoprecipitated using the FLAG antibody and immunoblotted for the indicated proteins.