CSF extract was supplemented with Myc-XErp1 wt IVT and treated with DMSO or CsA. Calcium was added, samples were taken at the indicated time points, resolved by either conventional or Phos-tagTM SDS-PAGE and immunoblotted for Cdc20, Cdc27 and cyclin B2. A control sample was treated with λ-phosphatase. A pseudocoloured representation of the Cdc20 and the Cdc27 immunoblots is shown in Fig. EV4A. The cyclin B2 membrane was stripped and reprobed for α-tubulin. 