Figure 2.

Rad17 regulates the interaction of 9-1-1 with TopBP1. (A) Mock-depleted (lane 1) and Rad17-depleted extracts supplemented with buffer (lane 2) or recombinant Rad17 (rRad17; lane 3) were immunoblotted for the indicated proteins. (B) The indicated extracts from A were incubated in the absence (lane 2) or presence of the FLAG-tagged BRCT I–II fragment of TopBP1 (lanes 3–5) for 1 h with anti-FLAG antibody beads. The beads were retrieved, and associated proteins were examined by immunoblotting with indicated antibodies. Rad9 (arrow) and the cross-reacting BRCT I–II band (asterisk) are marked. Lane 1 depicts 1.5 μl of initial egg extract.