Fig. 4. Identification of the phosphorylation motif in PLK3. (A) Phosphorylated PLK3 (PLK3^pS284) but not non-phosphorylated PLK3 (PLK3^npS284) or PLK1 is present in P190 IPs. (B) Phosphorylated PLK3 localizes to centrosomes, spindle poles and midbodies during mitosis. By contrast, non-phosphorylated PLK3 is more diffusely distributed than this during mitosis. The staining pattern of phosphorylated PLK3 is unaffected by blocking with the nonphosphorylated peptide (NP-Peptide) but disappears in the presence of the phosphorylated peptide (P-Peptide). (C) Phosphorylated PLK3 (green) localization partially overlaps with PLK1 (red) at centrosomes, spindle poles and midbodies, and with the CPC at midbodies.