Centractin
Encyclopedia
Centractin also known as ARP1 (Actin Related Protein-1) is a protein
found in the centrosome
and is a homologue
of the eukaryotic protein actin
. ARP1 forms a 37 nm filament-like structure and is the core of the dynactin
complex, an essential activator of cytoplasmic dynein-driven vesicle movement. It only exists in the dynactin complex in vivo. Highly purified, native Arp1 polymerize rapidly at extremely low concentrations into short filaments in vitro that were similar, but not identical, in length to those in dynactin. With time, these Arp1 filaments appeared to anneal to form longer assemblies but never attained the length of conventional actin
filaments. As for conventional actin, Arp1 can bind and hydrolyze ATP
, and Arp1 assembly is accompanied by nucleotide hydrolysis.
It has been reported that Arp1 interacts with other dynactin components including DCTN1
/p150Glued, DCTN4/p62 and Actr10/Arp11. Arp1 has been shown as the domain for dynactin binding to membrane vesicles (such as Golgi
or late endosome) through its association with β-spectrin
.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
found in the centrosome
Centrosome
In cell biology, the centrosome is an organelle that serves as the main microtubule organizing center of the animal cell as well as a regulator of cell-cycle progression. It was discovered by Edouard Van Beneden in 1883...
and is a homologue
Homology (biology)
Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...
of the eukaryotic protein actin
Actin
Actin is a globular, roughly 42-kDa moonlighting protein found in all eukaryotic cells where it may be present at concentrations of over 100 μM. It is also one of the most highly-conserved proteins, differing by no more than 20% in species as diverse as algae and humans...
. ARP1 forms a 37 nm filament-like structure and is the core of the dynactin
Dynactin
Dynactin or Dynein activator complex is a multi-subunit protein found in eukaryotic cells that aids in bidirectional intracellular transport by binding to dynein and Kinesin II and linking them to the organelle or vesicle to be transported....
complex, an essential activator of cytoplasmic dynein-driven vesicle movement. It only exists in the dynactin complex in vivo. Highly purified, native Arp1 polymerize rapidly at extremely low concentrations into short filaments in vitro that were similar, but not identical, in length to those in dynactin. With time, these Arp1 filaments appeared to anneal to form longer assemblies but never attained the length of conventional actin
Actin
Actin is a globular, roughly 42-kDa moonlighting protein found in all eukaryotic cells where it may be present at concentrations of over 100 μM. It is also one of the most highly-conserved proteins, differing by no more than 20% in species as diverse as algae and humans...
filaments. As for conventional actin, Arp1 can bind and hydrolyze ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
, and Arp1 assembly is accompanied by nucleotide hydrolysis.
It has been reported that Arp1 interacts with other dynactin components including DCTN1
DCTN1
Dynactin subunit 1 is a protein that in humans is encoded by the DCTN1 gene.- Function :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...
/p150Glued, DCTN4/p62 and Actr10/Arp11. Arp1 has been shown as the domain for dynactin binding to membrane vesicles (such as Golgi
Golgi
Golgi may refer to:*Camillo Golgi , Italian physician and scientist after which the following terms are named:**Golgi apparatus , an organelle in the eukaryotic cell...
or late endosome) through its association with β-spectrin
Spectrin
Spectrin is a cytoskeletal protein that lines the intracellular side of the plasma membrane of many cell types in pentagonal or hexagonal arrangements, forming a scaffolding and playing an important role in maintenance of plasma membrane integrity and cytoskeletal structure...
.