Figure 2.
Phosphorylation of SMC1 in response to IR is ATM- and NBS1-dependent. (a) Comparison of SMC1 phosphorylation kinetics in normal (GM00637) and A-T (GM05849) cell lines. Cells were irradiated with 10 Gy and incubated for indicated time periods. Cell lysates were analyzed by Western blotting. (b) Comparison of SMC1 phosphorylation in normal and A-T cells as a function of IR dosage. After receiving the indicated IR dosages, cells were incubated for 1 h. (c,d) Comparison of SMC1 phosphorylation in normal (IMR-90 and TK6) and NBS1-defective cells (GM07166 and JS). (e) Dependence of SMC1 phosphorylation on ATM. ATM fibroblasts FT169A and their ATM cDNA-complemented derivative cell line YZ5 were irradiated and analyzed for SMC1 phosphorylation. (f) Dependence of SMC1 and BRCA1 phosphorylation on NBS1. A GM07166 TERT cell line and its NBS1 cDNA-complemented derivative cell line were irradiated and analyzed for SMC1 and BRCA1 phosphorylation.