Fig. 1.

BubR1 binds Cdc20 through its N-terminus. (A) Schematic of full-length BubR1 and the various mutants. (B) Immunoblot showing expression of Myc-tagged BubR1 mutants in HeLa cells. Note that the anti-BubR1 antibody does not bind the ΔNT mutant. (C) Immunofluorescence images of mitotic HeLa cells showing kinetochore localisation of Myc-tagged wild-type BubR1, ΔNT and ΔKD. Insets show higher magnification view of selected kinetochores. Scale bars: 5 μm. (D) Immunoblots of Myc–BubR1 immune complexes isolated from HeLa cells treated with nocodazole for 16 hours and probed with antibodies against Myc, Bub3, Cdc20, Mad2 and Cdc27. (E) Bar graph quantifying the experiment in D. Values represent the mean ± s.e.m. of three independent experiments.