Figure 4.

MSH6-deficient cells exhibit prolonged γ-H2AX staining. (A) Control and MSH6-depleted HeLa cells were untreated (0 min) or treated with 100 ng/ml NCS. Whole-cell lysates were prepared at the indicated time points, and western-blot analysis was performed using specific antibodies directed against MSH6, MSH2, Ku70 and α-tubulin. (B and C) Control and MSH6-depleted HeLa cells were untreated or treated with 100 ng/ml NCS (B) or 5 Gy ionizing radiation (C) and were then fixed at the indicated times. Cells were stained with an anti-γ-H2AX antibody and the DNA was counterstained using DAPI. The percentage of γ-H2AX foci positive cells determined by confocal microcscopy (N = 3). Error bars represent the mean±SD. Asterisk denotes P < 0.01.