Dynactin

Overview
Dynactin or Dynein activator complex is a multi-subunit protein found in eukaryotic cells that aids in bidirectional intracellular organelle transport by binding to dynein and Kinesin II and linking them to the organelles to be transported.

Structure and mechanism of action
Dynactin consists of many subunits of which the p150Glued doublet (encoded by the DCTN1 gene) is the largest and has been found to be essential for function. This structure of dynactin is highly conserved in vertebrates. There are three isoforms encoded by a single gene.

Dynactin interacts with dynein directly by the binding of dynein intermediate chains with the p150 (glued homolog) doublet.

Functions
Dynactin is often essential for dynein activity and can be thought of as a "dynein receptor" that modulates binding of dynein to cell organelles which are to be transported along microtubules.

Dynactin is involved in various processes like chromosome alignment and spindle organization in cell division, maintaining nuclear position in addition to transport of various organelles in the cytoplasm. Dynactin also links Kinesin II to organelles.