Alpha-centractin (yeast) or ARP1 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the ''ACTR1A''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Function
This gene encodes a 42.6 kD subunit of
dynactin, 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. 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 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 ...
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/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
Spectrin is a cytoskeletal protein that lines the intracellular side of the plasma membrane in eukaryotic cells. Spectrin forms pentagonal or hexagonal arrangements, forming a scaffold and playing an important role in maintenance of plasma mem ...
.
Interactions
ACTR1A has been shown to
interact with
SPTBN2
Spectrin beta chain, brain 2 is a protein that in humans is encoded by the ''SPTBN2'' gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA th ...
.
References
Further reading
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External links
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* {{UCSC gene details, ACTR1A
Human proteins