Fig. 5. Dynamin proline-rich domain binds directly to cortactin. (A) Far-western blot analysis of interaction between cortactin and dynamin PRD. Recombinant His-cortactin, Arp2/3 complex and actin protein were subjected to SDS-PAGE followed by Coomassie Blue staining (upper panel) or transferred to a cellulose membrane and then incubated with a fusion protein containing dynamin PRD (GST-Dyn-PRD). Binding of GST-Dyn-PRD to cortactin was detected by anti-GST antibody (lower panel). (B) GST-Dyn-PRD or GST were immobilized on glutathione beads and incubated with cytosolic extracts of NIH3T3 cells at 4°C for 2 hours. Cortactin binding to beads was detected by immunoblot. The amino acid sequence of PRD in GST-Dyn-PRD, corresponding to rat dynamin 2 C-terminus, is presented in the lower panel.