Fig. 7. The Brf1–Bdp1 interaction may be compromised specifically at mitosis. (A) Reticulocyte lysate (10 µl) containing in vitro-translated Brf1 was mixed with extract (150 µg) of asynchronous (lanes 2 and 4) or metaphase-arrested HeLa cells (lanes 3 and 5) prior to immunoprecipitation with anti-Bdp1 antiserum (lanes 2 and 3) or pre-immune serum (lanes 4 and 5). Proteins retained after extensive washing were resolved by SDS–PAGE and visualized by autoradiography. Lane 1 shows 20% of the input reticulocyte lysate. (B) As above, except that 20% input is shown in lane 5 and the immunoprecipitations used anti-TBP antibody (lanes 1 and 2) or pre-immune serum (lanes 3 and 4).