Destrin or DSTN (also known as actin depolymerizing factor or ADF) 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, res ...
which in humans is encoded by the ''DSTN''
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 b ...
.
Destrin is a component protein in
microfilament
Microfilaments, also called actin filaments, are protein filaments in the cytoplasm of eukaryotic cells that form part of the cytoskeleton. They are primarily composed of polymers of actin, but are modified by and interact with numerous other pr ...
s.
The product of this gene belongs to the
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 ov ...
-binding proteins ADF (Actin-Depolymerizing Factor)/
cofilin
ADF/cofilin is a family of actin-binding proteins associated with the rapid depolymerization of actin microfilaments that give actin its characteristic dynamic instability. This dynamic instability is central to actin's role in muscle contractio ...
family. This family of proteins is responsible for enhancing the turnover rate of actin in vivo. This gene encodes the actin depolymerizing protein that severs actin filaments (F-actin) and binds to actin monomers (G-actin). Two transcript variants encoding distinct isoforms have been identified for this gene.
Structure
The tertiary structure of destrin was determined by the use of triple-resonance multidimensional nuclear magnetic resonance,
NMR
Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are perturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with ...
.
The secondary and tertiary structures of destrin are similar to the
gelsolin
Gelsolin is an actin-binding protein that is a key regulator of actin filament assembly and disassembly. Gelsolin is one of the most potent members of the actin-severing gelsolin/ villin superfamily, as it severs with nearly 100% efficiency.
Cell ...
family which is another actin-regulating protein family.
There are three ordered layers to destrin which is a globular protein. There is a central
β sheet
The beta sheet, (β-sheet) (also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a g ...
that is composed of one parallel strand and three antiparallel strands. This β sheet is between a long
α helix
The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues ...
along with a shorter one and two shorter helices on the opposite side. The four helices are parallel to the β strands.
Function
In a variety of
eukaryotes, destrin regulates actin in the cytoskeleton. Destrin binds actin and is thought to connect it as gelsolin segment-1 does. Furthermore, the binding of actin by destrin and cofilin is regulated negatively by phosphorylation. Destrin can also sever actin filaments.
References
External links
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Ramachandran Plot
In biochemistry, a Ramachandran plot (also known as a Rama plot, a Ramachandran diagram or a †,ψplot), originally developed in 1963 by G. N. Ramachandran, C. Ramakrishnan, and V. Sasisekharan, is a way to visualize energetically allowed regions ...
for destrin:
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