Mitotic kinases regulate MT-polymerizing/MT-bundling activity of DDA3

► DDA3 is hyper-phosphorylated mitotic protein. ► DDA3 is phosphorylated by Plk1, Aurora A, and Cdk1 in vitro. ► Phosphorylation down-regulates MT-polymerizing and MT-bundling activities of DDA3. ► Aurora A and Cdk1 negatively regulate MT-polymerizing and MT-bundling activities of DDA3.