Alpha-centractin (yeast) or ARP1 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the ''ACTR1A''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
Function
This gene encodes a 42.6 kD subunit of
dynactin
Dynactin is a 23 Protein subunit, subunit protein complex that acts as a co-factor for the microtubule motor cytoplasmic dynein-1. It is built around a short filament of actin related protein-1 (ACTR1A, Arp1).
Discovery
Dynactin was identified a ...
, a macromolecular complex consisting of 10-11 subunits ranging in size from 22 to 150 kD. Dynactin binds to both
microtubules
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nm and have an inner diameter between 11 an ...
and
cytoplasmic dynein
Dyneins are a family of cytoskeletal motor proteins that move along microtubules in cells. They convert the chemical energy stored in ATP to mechanical work. Dynein transports various cellular cargos, provides forces and displacements important ...
. 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 is present in 8-13 copies per dynactin molecule, and is the most abundant molecule in the dynactin complex. It is an actin-related protein, and is approximately 60% identical at the amino acid level to conventional actin.
ARP1 forms a 37 nm filament-like structure and is the core of the
dynactin
Dynactin is a 23 Protein subunit, subunit protein complex that acts as a co-factor for the microtubule motor cytoplasmic dynein-1. It is built around a short filament of actin related protein-1 (ACTR1A, Arp1).
Discovery
Dynactin was identified a ...
complex.
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 is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of over ...
filaments. As for conventional actin, Arp1 can bind and hydrolyze
ATP
ATP may refer to:
Companies and organizations
* Association of Tennis Professionals, men's professional tennis governing body
* American Technical Publishers, employee-owned publishing company
* ', a Danish pension
* Armenia Tree Project, non ...
, and Arp1 assembly is accompanied by nucleotide hydrolysis.
It has been reported that Arp1 interacts with other dynactin components including
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 23 subunits (11 individual proteins ranging in size from 22 to ...
/p150
Glued,
/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.
Interactions
ACTR1A has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with
SPTBN2
Spectrin beta chain, brain 2 is a protein that in humans is encoded by the ''SPTBN2'' gene.
Clinical significance
Mutations in this gene is associated with Spinocerebellar ataxia type 5.
Interactions
SPTBN2 has been shown to interact with:
* ...
.
References
Further reading
*
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External links
*
* {{UCSC gene details, ACTR1A
Human proteins