Member of the pointed-end complex of the dynactin shoulder complex which contains DCTN4, DCTN5 and DCTN6 subunits and ACTR10. Within the complex DCTN6 forms a heterodimer with DCTN5. Interacts with PLK1 (By similarity). Up-regulated in Ant1-deficient mice. Phosphorylation at Thr-186 by CDK1 during mitotic prometaphase creates a binding site for PLK1 that facilitates its recruitment to kinetochores. Belongs to the dynactin subunits 5/6 family. Dynactin subunit 6 subfamily.