Tyrosine

Tyrtyrosine metabolismL-tyrosinephosphotyrosineYtyrosines L -tyrosineTtyrosyl-tyrosine
Tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins.wikipedia
854 Related Articles

Essential amino acid

essential amino acidsessentialnon-essential amino acid
It is a non-essential amino acid with a polar side group.
These six are arginine, cysteine, glycine, glutamine, proline, and tyrosine.

Phenylalanine

PheL-phenylalaninephenylalanine metabolism
While tyrosine is generally classified as a hydrophobic amino acid, it is more hydrophilic than phenylalanine.
Phenylalanine is a precursor for tyrosine, the monoamine neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), and the skin pigment melanin.

Protein kinase

protein kinasestransmembranekinases
It occurs in proteins that are part of signal transduction processes and functions as a receiver of phosphate groups that are transferred by way of protein kinases. Some of the tyrosine residues can be tagged (at the hydroxyl group) with a phosphate group (phosphorylated) by protein kinases.
Most kinases act on both serine and threonine (serine/threonine kinases), others act on tyrosine (tyrosine kinases), and a number act on all three (dual-specificity kinases).

Proteinogenic amino acid

proteinogenicamino acidsList of standard amino acids
It is a non-essential amino acid with a polar side group. Tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins.

Photosynthesis

photosyntheticphotosynthesizephotosynthesizing
A tyrosine residue also plays an important role in photosynthesis.
The electrons yielded are transferred to a redox-active tyrosine residue that then reduces the oxidized P680.

Signal transduction

signaling pathwayssignaling cascadesignal transduction pathways
It occurs in proteins that are part of signal transduction processes and functions as a receiver of phosphate groups that are transferred by way of protein kinases.
The interaction between the cytoplasmic domains stimulates the autophosphorylation of tyrosine residues within the intracellular kinase domains of the RTKs, causing conformational changes.

Tyrosine hydroxylase

THtyrosine 3-monooxygenasetyrosine
In dopaminergic cells in the brain, tyrosine is converted to L-DOPA by the enzyme tyrosine hydroxylase (TH).
Tyrosine hydroxylase or tyrosine 3-monooxygenase is the enzyme responsible for catalyzing the conversion of the amino acid L -tyrosine to L -3,4-dihydroxyphenylalanine ( L -DOPA).

L-DOPA

levodopa L -DOPADOPA
In dopaminergic cells in the brain, tyrosine is converted to L-DOPA by the enzyme tyrosine hydroxylase (TH).
Humans, as well as a portion of the other animals that utilize -DOPA in their biology, make it via biosynthesis from the amino acid -tyrosine.

Phenylalanine hydroxylase

PAHEC 1.14.16.1phenylalanine
The conversion of phe to tyr is catalyzed by the enzyme phenylalanine hydroxylase, a monooxygenase.
Phenylalanine hydroxylase (PAH) is an enzyme that catalyzes the hydroxylation of the aromatic side-chain of phenylalanine to generate tyrosine.

Prephenic acid

prephenatedisodium prephenate
In plants and most microorganisms, tyr is produced via prephenate, an intermediate on the shikimate pathway.
Prephenic acid, commonly also known by its anionic form prephenate, is an intermediate in the biosynthesis of the aromatic amino acids phenylalanine and tyrosine, as well as of a large number of secondary metabolites of the shikimate pathway.

Shikimate pathway

shikimic acid pathwaypathwayShikimate acid pathway
In plants and most microorganisms, tyr is produced via prephenate, an intermediate on the shikimate pathway.
The shikimate pathway (shikimic acid pathway) is a seven-step Metabolic pathway used by bacteria, archaea, fungi, algae, some protozoans, and plants for the biosynthesis of folates and aromatic amino acids (phenylalanine, tyrosine, and tryptophan).

Thyroid hormones

thyroid hormonethyroxineT4
The thyroid hormones triiodothyronine (T 3 ) and thyroxine (T 4 ) in the colloid of the thyroid also are derived from tyrosine.
They are tyrosine-based hormones that are primarily responsible for regulation of metabolism.

Catecholamine

catecholaminescatecholamine synthesiscatecholamine systems
Dopamine can then be converted into other catecholamines, such as norepinephrine (noradrenaline) and epinephrine (adrenaline).
Catecholamines are derived from the amino acid tyrosine, which is derived from dietary sources as well as synthesis from phenylalanine.

Dopamine

dopaminergic systemDAdopaminergic
TH is the rate-limiting enzyme involved in the synthesis of the neurotransmitter dopamine.
The direct precursor of dopamine, L -DOPA, can be synthesized indirectly from the essential amino acid phenylalanine or directly from the non-essential amino acid tyrosine.

Tyrosine sulfation

sulfationsulfatedsulfated tyrosine
Tyrosine residues may also be modified by the addition of a sulfate group, a process known as tyrosine sulfation.
Tyrosine sulfation is a posttranslational modification where a sulfate group is added to a tyrosine residue of a protein molecule.

Neurotransmitter

neurotransmittersexcitatory neurotransmitterneurotransmitter system
TH is the rate-limiting enzyme involved in the synthesis of the neurotransmitter dopamine.
L-phenylalanine and L-tyrosine are both precursors for dopamine, norepinephrine, and epinephrine.

Norepinephrine

noradrenalinenoradrenergicnoradrenalin
Dopamine can then be converted into other catecholamines, such as norepinephrine (noradrenaline) and epinephrine (adrenaline).
Norepinephrine is synthesized from the amino acid tyrosine by a series of enzymatic steps in the adrenal medulla and postganglionic neurons of the sympathetic nervous system.

Melanin

eumelaninpheomelaninphaeomelanin
Tyrosine is also the precursor to the pigment melanin.
Melanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine is followed by polymerization.

Tyrosine aminotransferase

tyrosine transaminaseTAT
para-hydroxyphenylalanine) begins with an α-ketoglutarate dependent transamination through the tyrosine transaminase to para-hydroxyphenylpyruvate.
Tyrosine aminotransferase (or tyrosine transaminase) is an enzyme present in the liver and catalyzes the conversion of tyrosine to 4-hydroxyphenylpyruvate.

4-Hydroxyphenylpyruvate dioxygenase

HPDp''-hydroxyphenylpyruvate dioxygenaseEC 1.13.11.27
The next oxidation step catalyzes by p-hydroxyphenylpyruvate dioxygenase and splitting off CO2 homogentisate (2,5-dihydroxyphenyl-1-acetate).
4-Hydroxyphenylpyruvate dioxygenase (HPPD), also known as α-ketoisocaproate dioxygenase (KIC dioxygenase), is an Fe(II)-containing non-heme oxygenase that catalyzes the second reaction in the catabolism of tyrosine - the conversion of 4-hydroxyphenylpyruvate into homogentisate.

Thyroid

thyroid glandthyroid folliclethyroid function
The thyroid hormones triiodothyronine (T 3 ) and thyroxine (T 4 ) in the colloid of the thyroid also are derived from tyrosine.
The thyroid hormones are created from iodine and tyrosine.

Alkaloid

alkaloidspurine alkaloidalkaloid biosynthesis
The latex of Papaver somniferum, the opium poppy, has been shown to convert tyrosine into the alkaloid morphine and the bio-synthetic pathway has been established from tyrosine to morphine by using Carbon-14 radio-labelled tyrosine to trace the in-vivo synthetic route.
More recent classifications are based on similarity of the carbon skeleton (e.g., indole-, isoquinoline-, and pyridine-like) or biochemical precursor (ornithine, lysine, tyrosine, tryptophan, etc.).

Phosphorylation

phosphorylatedphosphorylatephosphorylates
Some of the tyrosine residues can be tagged (at the hydroxyl group) with a phosphate group (phosphorylated) by protein kinases.
Phosphorylation can occur on serine, threonine and tyrosine side chains (often called 'residues') through phosphoester bond formation, on histidine, lysine and arginine through phosphoramidate bonds, and on aspartic acid and glutamic acid through mixed anhydride linkages.

Triiodothyronine

T 3 T3triiodothyronine (T3)
The thyroid hormones triiodothyronine (T 3 ) and thyroxine (T 4 ) in the colloid of the thyroid also are derived from tyrosine.
In the follicular lumen, tyrosine residues become iodinated.

Papaver somniferum

opium poppyopium poppiespoppy
The latex of Papaver somniferum, the opium poppy, has been shown to convert tyrosine into the alkaloid morphine and the bio-synthetic pathway has been established from tyrosine to morphine by using Carbon-14 radio-labelled tyrosine to trace the in-vivo synthetic route.
First, the amino acid phenylalanine, through the enzyme phenylalanine hydroxylase, is transformed into tyrosine.