Serine/threonine-protein kinase LMTK1 (also known as Apoptosis-associated tyrosine kinase) is an
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
that in humans is encoded by the (''AATK'')
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 ...
.
Structure and expression
The gene was identified in 1998. It is located on chromosome 17 (17q25.3) and is expressed in the pancreas, kidney, brain and lungs. The protein is composed of 1,207 amino acids.
Function
The protein contains a
tyrosine kinase
A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to the tyrosine residues of specific proteins inside a cell. It functions as an "on" or "off" switch in many cellular functions.
Tyrosine kinases belong to a larger cla ...
domain at the
N-terminal
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amin ...
end and a
proline
Proline (symbol Pro or P) is an organic acid classed as a proteinogenic amino acid (used in the biosynthesis of proteins), although it does not contain the amino group but is rather a secondary amine. The secondary amine nitrogen is in the p ...
-rich domain at the
C-terminal
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, carboxy tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When t ...
end. Studies of the mouse homologue have indicated that it may be necessary for the induction of growth arrest and/or
apoptosis
Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...
of
myeloid precursor cells. It may also have a role in inducing differentiation in neuronal cells.
Its suppressive role on
melanoma
Melanoma is the most dangerous type of skin cancer; it develops from the melanin-producing cells known as melanocytes. It typically occurs in the skin, but may rarely occur in the mouth, intestines, or eye (uveal melanoma). In very rare case ...
development has been reported recently.
AATK is thought to indirectly inhibit the
SPAK
Special Structure against Corruption and Organized Crime (, SPAK) is an independent judicial entity tasked with investigating corruption and organized crime at the highest levels of government and society in Albania.
Τhe legal basis of the entity ...
/
WNK4
Serine/threonine protein kinase WNK4 also known as With No lysine (K) protein kinase 4 (WNK4), is an enzyme that in humans is encoded by the ''WNK4'' gene. Missense mutations cause a genetic form of pseudohypoaldosteronism type 2, also called Gor ...
activation of the
Na-K-Cl cotransporter.
References
Further reading
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External links
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Genes on human chromosome 17
Tyrosine kinase receptors
{{Transmembranereceptor-stub