Fig. 3. Dup is associated with CDK2 protein and activity in embryo extracts. (A) Dup immunoprecipitates Myc:CDK2 from embryo extracts. Extracts from da:GAL4; UAS:6XMyc:CDK2 embryos were used for immunoprecipitation with antibodies to Dup (lane 1), Myc (lane 2) or with pre-immune sera (lane 3) and western blots were subsequently probed for Myc. The asterisk indicates the mouse immunoglobulin band. (B) Dup is associated with a CDK kinase activity. Dup antibody (lanes 1 and 2) or pre-immune serum (lane 3) was used for immunoprecipitation from wild-type embryos (lane 1) or those expressing 6XMyc:CDK2 (lanes 2 and 3), and the pellet was subsequently used in an in vitro kinase assay with ³²P[ATP] and histone H1 as substrate.