Fig. 1. Cyclin B interacts with Hsp90 and Msps. (A) A Coomassie-Blue-stained gel of the proteins that bind to MBP-CBFL after incubation with embryo extract. Lane 1, the high speed embryo extract that was loaded onto the amylose column; lane 2, the proteins that flowed through the amylose column; lane 3, the proteins that were eluted from the amylose column. The MBP-CBFL protein is highlighted with a black arrow. Hsp90 (Hsp83) and Msps are indicated with black arrowheads. (B) A western blot analysis of an immunoprecipitation experiment performed with Drosophila embryo extracts (lane 1), random rabbit IgG (lane 2), affinity-purified anti-cyclin B antibody (lane 3), affinity-purified anti-Msps antibody (lane 4) and anti-Hsp90 antibody (lane 5). The membrane was probed with anti-Msps, anti-Hsp90 and anti-cyclin B antibodies as indicated. (C) A schematic diagram of the MBP cyclin B fusion proteins used in the MBP pull-down experiment shown in D: MBP-cyclin B full length (MBP-CBFL); MBP-cyclin B N-terminal (MBP-CBNT; contains the D-box and N-terminal helix, but no cyclin boxes); MBP-cyclin B C-terminal 1 (MBP-CBC1; contains the N-terminal helix and the two cyclin boxes); MBP-cyclin B C terminal 2 (MBP-CBC2; contains only the two cyclin boxes). (D) A western blot of an MBP pull-down experiment performed with affinity-purified anti-MBP antibodies and probed with anti-Hsp90 and anti-Msps antibodies as indicated.