Fig. 2. S1126 phosphorylation is mitotic-specific. (A) Anti-Myc immunoprecipitates from cells synchronised with thymidine, nocodazole or taxol, showing that separase is phosphorylated and bound to cyclin B1 only in mitotic-enriched populations. MI represents the mitotic index (%) of the population. (B) Cyclin B1 immunoprecipitations from asynchronous or nocodazole-treated HeLa cells showing that phosphorylated separase is present in the immune complex isolated from the nocodazole-treated sample.