FIG. 1.
IR-induced Nbs1 phosphorylation is compromised in A-TLD2 but not in A-TLD3 or NBS cells. (A) Nbs1p70 is phosphorylated after IR. NBS cells were irradiated with 20 Gy (+) or were mock treated (−) and harvested at 45 min post-IR. Nbs1 immunoprecipitations and lambda phosphatase treatments (λ PP) were performed, resolved by SDS-PAGE, and immunoblotted with Nbs1 antiserum. The migration of a 68-kDa molecular size marker protein is indicated. (B) Lymphoblasts from two different A-TLD patients (A-TLD2 and A-TLD3), A-T lymphoblasts (AT3LA), and a normal control (721) were mock treated (−) or irradiated (+) with 20 Gy and harvested for analysis at 45 min after treatment. Nbs1 immunoprecipitations were performed, and each immunoprecipitation reaction mixture was either mock treated (−) or treated with lambda phosphatase (+) as described for panel A.