This gene encodes the largest subunit of dynactin, a macromolecular complex consisting of 10-11 subunits ranging in size from 22 to 150 kD. Dynactin binds to both microtubules and cytoplasmic dynein. It is involved in a diverse array of cellular functions, including ER-to-Golgi transport, the centripetal movement of lysosomes and endosomes, spindle formation, chromosome movement, nuclear positioning, and axonogenesis. This subunit interacts with dynein intermediate chain by its domains directly binding to dynein. Alternative splicing of this gene results in at least 2 functionally distinct isoforms: a ubiquitously expressed one and a brain-specific one. Based on its cytogenetic location, this gene is considered as a candidate gene for limb-girdle muscular dystrophy.