About DCTN / Dynactin:
Dynactin, or DCTN is a 23-subunit protein that is important for the correct functioning of the microtubule - cytoplasmic dynein. It was found to be built around a filament of actin-related protein-1. It is named Dynactin because it has an important role in dynein activation and is absolutely essential for a range of functions.
Yet, despite a significant amount of scientific research, the mechanism for dynactin’s role in activating dynein have remained unclear. There are a number of theories as to the answer, with none yet being definitively proven.
DCTN Structure
Research into DCTN has led to the identification of three major structures that form CTN.
1.Sidearm-shoulder - DCTN1/p150Glued, DCTN2/p50/dynamitin, DCTN3/p24/p22
2.Arp-1 filament - ACTR1A/Arp1/centractin, actin, CapZ
3.Pointed end complex
Dynactin Functions
DCTN has been found to be essential to dynein activity and modulates the binding of the dynein to organelles as they are being transported along the microtubules. It is involved in the processes of cell division, chromosome alignment and spindle organization.
It has also been found in organisms such as Drosophila, Funghi and zebrafish to effectively maintain the nuclear position.
DCTN Interactions
It is thought that DCTN reacts directly with the microtubule minus ends. DCTN’s cargo-binding subunits can associate with a range of intracellular molecules.
DCTN and dynein have been shown to act directly through the dynein intermediate chains binding with p150.
When BICD2 is present, DCTN will bind itself to the dynein and then activate it to move along at increasing distances along the microtubules.