Tyrosine Hydroxylase (TH)

Tyrosine hydroxylase (TH) is a rate-limiting enzyme in catecholamine synthesis. Tyrosine hydroxylase activity is modulated by protein-protein interactions with enzymes in the same pathway or the tetrahydrobiopterin pathway, structural proteins considered to be chaperones that mediate the neuron's oxidative state, and the protein that transfers dopamine into secretory vesicles. It is phosphorylated at serine (Ser) residues Ser8, Ser19, Ser31 and Ser40 in vitro. The phosphorylation of tyrosine hydroxylase at Ser19 or Ser8 has no direct effect on tyrosine hydroxylase activity. As tyrosine hydroxylase (TH) catalyses the formation of L-DOPA, the rate-limiting step in the biosynthesis of DA, the Parkinson's disease (PD) can be considered as a TH-deficiency syndrome of the striatum. A direct pathogenetic role of TH has also been suggested, as the enzyme is a source of reactive oxygen species (ROS) in vitro and a target for radical-mediated oxidative injury. Recently, it has been demonstrated that L-DOPA is effectively oxidized by mammalian Tyrosine hydroxylase in vitro, possibly contributing to the cytotoxic effects of DOPA.

Tyrosine Hydroxylase (TH) Related Areas

Enzyme>>Other>>Tyrosine Hydroxylase

Tyrosine Hydroxylase (TH) Alternative Names

Tyrosine Hydroxylase, TH, DYT14, DYT5b, TYH [Homo sapiens]

Tyrosine Hydroxylase, Th, OTTMUSP00000020341, tyrosine 3-hydroxylase, tyrosine 3-monooxygenase [Mus musculus]

Summaries for Tyrosine Hydroxylase (TH)

Entrez Gene summary for Tyrosine Hydroxylase (TH):

The protein encoded by TH gene is involved in the conversion of tyrosine to dopamine. It is the rate-limiting enzyme in the synthesis of catecholamines, hence plays a key role in the physiology of adrenergic neurons. Mutations in TH gene have been associated with autosomal recessive Segawa syndrome. Alternatively spliced transcript variants encoding different isoforms have been noted for TH gene. [provided by RefSeq, Jul 2008]

OMIM - description for Tyrosine Hydroxylase (TH):

Tyrosine hydroxylase is involved in the conversion of phenylalanine to dopamine. As the rate-limiting enzyme in the synthesis of catecholamines, tyrosine hydroxylase has a key role in the physiology of adrenergic neurons.

Wikipedia summary for 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). It does so using molecular oxygen (O₂), as well as iron (Fe²⁺) and tetrahydrobiopterin as cofactors. L-DOPA is a precursor for dopamine, which, in turn, is a precursor for the important neurotransmitters norepinephrine (noradrenaline) and epinephrine (adrenaline). Tyrosine hydroxylase catalyzes the rate limiting step in this synthesis of catecholamines. In humans, tyrosine hydroxylase is encoded by the TH gene, and the enzyme is present in the central nervous system (CNS), peripheral symphatic neurons and the adrenal medulla. Tyrosine hydroxylase, phenylalanine hydroxylase and tryptophan hydroxylase together make up the family of aromatic amino acid hydroxylases (AAAHs).

Human Tyrosine Hydroxylase (TH) Protein General Information

 

• Protein names: Tyrosine Hydroxylase
  Short name=TH
• Sequence length: 497 AA.
• Sequence status: Complete.
• Protein existence: Evidence at transcript level

General information above from UniProt

Function for Tyrosine Hydroxylase (TH) Protein

Genatlas:

• Tyrosine hydroxylase is tyrosine 3-monooxygenase
• Tyrosine hydroxylase is potentially associated with longevity in the male
• Tyrosine hydroxylase catalyzes the rate limiting step in the biosynthesis of catecholamines in the central and peripheral nervous system
• The promoter is able to direct GFP expression to TH+ neurons of substantia nigra

Homology for human Tyrosine Hydroxylase (TH)

• homolog to murine Th

Phenotype Information for Tyrosine Hydroxylase (TH)

• Gene/Locus: TH, TYH
• Phenotype: Segawa syndrome, recessive

Phenotype Information for Tyrosine Hydroxylase (TH) from OMIM (Online Mendelian Inheritance in Man)