Pointed-end-associated component of the dynactin complex which assists cytoplasmic dynein by increasing its processivity and by regulation of its cargo binding (By similarity). The dynactin complex is required for the spindle translocation late in anaphase and is involved in a cell wall synthesis checkpoint. May regulate the association of the dynactin complex with the plasma membrane. Self-associates. Component of the dynactin complex composed of at least ARP1, JNM1, NIP100 and ARP10. Dynactin comprises a short rod of the ARP1 filament attached to ARP10 at its pointed-end and probably associated with the capping protein at its barbed-end. The rod is implicated in dynein cargo binding. A sidearm formed by NIP100 projects from the ARP1 filament and is implicated in motor binding (By similarity). Interacts with ARP1 and JNM1. Belongs to the actin family. ARP10 subfamily.