Figure 2

<p>Cyclin B1 abundance and MPF activity in CSF-arrested extracts. (<i>A</i>) Cyclin B, cdk1-phospho-tyr15, cdk1, cdc25C-phospho-ser-287 and cdc25C contents from total extract samples of a CSF-arrested extract, pre-incubated with [³⁵S]methionine, at the indicated time points after CaCl₂ addition. (<i>B</i>) Left panels, cyclin B1, cyclin B1-associated kinase activity, cdk1-phospho-tyr15 and cdk1 contents in cyclin B1 Ips from CSF-arrested extract samples at the indicated time points after CaCl₂ addition. Right, quantisation of cyclin B1 content (open squares), cyclin B1-associated kinase activity (filled squares) from cyclin B1 Ips.