Figure 2.

Geminin blocks UV-induced accumulation of checkpoint and replication proteins on chromatin. (A) Binding of xATR, xRad1, and xORC2 to chromatin in interphase extract was assayed after mock, UV, or aphidicolin (APH) treatment. Chromatin (2000/μL) was isolated at the given time points, and chromatin-bound proteins were analyzed by Western blotting with antibodies to xATR, xRad1, or xORC2. (B) Chromatin binding of the p180 subunit of xPolα, xRPA70, and xORC2 was assayed after mock, UV, and aphidicolin treatment by Western blotting. Samples were treated and prepared as described in A. (C) Interphase extract was pretreated for 10 min with geminin (+gem) before addition of mock- or UV-treated chromatin (2000/μL). Chromatin was isolated after 100 min, and chromatin-bound proteins were analyzed as described above.