Annexin A2 also known as annexin II 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, respon ...
that in humans is encoded by the ''ANXA2''
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 ...
.
Annexin 2 is involved in diverse cellular processes such as
cell motility (especially that of the
epithelial cells
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellu ...
), linkage of membrane-associated protein complexes to the actin
cytoskeleton
The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is comp ...
,
endocytosis
Endocytosis is a cellular process in which substances are brought into the cell. The material to be internalized is surrounded by an area of cell membrane, which then buds off inside the cell to form a vesicle containing the ingested material. E ...
, fibrinolysis,
ion channel
Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ...
formation, and
cell matrix interactions.
It is a calcium-dependent phospholipid-binding protein whose function is to help organize
exocytosis
Exocytosis () is a form of active transport and bulk transport in which a cell transports molecules (e.g., neurotransmitters and proteins) out of the cell ('' exo-'' + '' cytosis''). As an active transport mechanism, exocytosis requires the use ...
of intracellular proteins to the extracellular domain. Annexin II is a
pleiotropic protein meaning that its function is dependent on place and time in the body.
Gene
The ANXA2 gene, located at 15q22.2, has three pseudogenes located on chromosomes 4, 9 and 10, respectively. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene.
Function
This protein is a member of the
annexin
Annexin is a common name for a group of cellular proteins. They are mostly found in eukaryotic organisms (animal, plant and fungi).
In humans, the annexins are found inside the cell (biology), cell. However some annexins (Annexin A1, Annexin A2, ...
family. Members of this calcium-dependent phospholipid-binding protein family play a role in the regulation of cellular growth and in signal transduction pathways. This protein functions as an autocrine factor which heightens osteoclast formation and bone resorption.
Epigenetic regulation of Annexin A2 has been identified as a key determinant of mesenchymal transformation in brain tumors.
Maternal deficiency of the ANXA2 gene contributes to shallow decidual invasion by placental cytotrophoblast cells. These findings highlight the maternal contribution to the pathogenesis of severe
preeclampsia.
Annexin A2 has been proposed to function inside the cell in sorting of
endosomes and outside the cell in
anticoagulant
Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where t ...
reactions.
Interactions
Annexin A2 has been shown to
interact with
Prohibitin,
,
,
,
complement
Factor H
Factor H is a member of the regulators of complement activation family and is a complement control protein. It is a large (155 kilodaltons), soluble glycoprotein that circulates in human plasma (at typical concentrations of 200–300 microgram ...
,
and a number of viral factors including the
HPV16 minor
capsid protein L2.
See also
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Annexin
Annexin is a common name for a group of cellular proteins. They are mostly found in eukaryotic organisms (animal, plant and fungi).
In humans, the annexins are found inside the cell (biology), cell. However some annexins (Annexin A1, Annexin A2, ...
References
Further reading
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External links
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{{Calcium-binding proteins
Peripheral membrane proteins