Lysyl oxidase homolog 2 is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
that in humans is encoded by the ''LOXL2''
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 ...
.
Function
This gene encodes a member of the
lysyl oxidase
Lysyl oxidase (LOX), also known as protein-lysine 6-oxidase, is an enzyme that, in humans, is encoded by the ''LOX'' gene. It catalyzes the conversion of lysine molecules into highly reactive aldehydes that form cross-links in extracellular matr ...
gene family. The prototypic member of the family is essential to the
biogenesis
Spontaneous generation is a superseded scientific theory that held that living creatures could arise from nonliving matter and that such processes were commonplace and regular. It was hypothesized that certain forms, such as fleas, could arise ...
of connective tissue, encoding an extracellular copper-dependent amine oxidase that catalyses the first step in the formation of crosslinks in
collagens and
elastin. A highly conserved amino acid sequence at the
C-terminus end appears to be sufficient for amine oxidase activity, suggesting that each family member may retain this function. The
N-terminus is poorly conserved and may impart additional roles in developmental regulation, senescence, tumor suppression, cell growth control, and
chemotaxis to each member of the family.
LOXL2 can also crosslink
collagen type IV
Collagen IV (ColIV or Col4) is a type of collagen found primarily in the basal lamina. The type IV collagen C4 domain, collagen IV C4 domain at the C-terminus is not removed in post-translational processing, and the fibers link head-to-head, rathe ...
and hence influence the sprouting of new
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...
vessels.
Clinical significance
LOXL2 is an enzyme that is up-regulated in several types of cancer and is associated with a poorer prognosis.
LOXL2 changes the structure of
histone
In biology, histones are highly basic proteins abundant in lysine and arginine residues that are found in eukaryotic cell nuclei. They act as spools around which DNA winds to create structural units called nucleosomes. Nucleosomes in turn a ...
s (proteins that are attached to DNA) and thus changes the shape of the cells, making it easier for the cancer cells to
metastasize
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...
.
An antibody that inhibits the activity of LOXL2,
simtuzumab and is currently in clinical trials for the treatment of several types of cancer and fibrotic diseases such as
liver fibrosis
Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis due to damage caused by liver disease. Damage causes tissue repai ...
.
See also
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LOXL1
Lysyl oxidase homolog 1, also known as LOXL1, is an enzyme which in humans is encoded by the ''LOXL1'' gene.
Function
This gene encodes a member of the lysyl oxidase gene family. The prototypic member of the family is essential to the biogenesi ...
*
LOXL3
Lysyl oxidase homolog 3 is an enzyme that in humans is encoded by the ''LOXL3'' gene.
This gene encodes a member of the lysyl oxidase gene family. The prototypic member of the family is essential to the biogenesis of connective tissue, encoding an ...
*
LOXL4
Lysyl oxidase homolog 4 is an enzyme that in humans is encoded by the ''LOXL4'' gene.
This gene encodes a member of the lysyl oxidase gene family. The prototypic member of the family is essential to the biogenesis of connective tissue, encoding a ...
References
External links
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Further reading
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Lysyl oxidases
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