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. JNM1 is associated with the rod and links it to the projecting sidearm. Required for proper nuclear migration during the mitotic cell cycle and for astral microtubule development. Component of the dynactin complex composed of at least ARP1, JNM1, NIP100 and ARP10. Dynactin comprises a short rod of ARP1 polymers attached to ARP10 at its pointed-end and probably associated with the capping protein at its barbed-end. The rod structure 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.