TH : tyrosine hydroxylase
Description
The TH (tyrosine hydroxylase) is a protein-coding gene located on chromosome 11.
The TH gene provides instructions for making the enzyme tyrosine hydroxylase, which is essential for the normal functioning of the nervous system. Tyrosine hydroxylase is involved in the first step of the pathway that produces catecholamines, a group of chemical messengers crucial for the autonomic nervous system. The autonomic nervous system regulates involuntary processes like blood pressure and body temperature. Catecholamines are released in response to physical or emotional stress and transmit signals between brain cells and other cells in the body. Tyrosine hydroxylase converts the amino acid tyrosine to L-DOPA, which is further converted to dopamine. Other catecholamines, norepinephrine and epinephrine, are derived from dopamine.
Tyrosine hydroxylase (TH) catalyzes the conversion of L-tyrosine to L-dihydroxyphenylalanine (L-Dopa), the rate-limiting step in the biosynthesis of catecholamines, including dopamine, noradrenaline, and adrenaline. It utilizes tetrahydrobiopterin and molecular oxygen to facilitate this conversion. While primarily acting on tyrosine, TH can also catalyze the hydroxylation of phenylalanine and tryptophan, albeit with lower specificity. TH plays a role in the regression of retinal hyaloid vessels during postnatal development.
TH is also known as DYT14, DYT5b, TYH.
Associated Diseases
- Autosomal recessive dopa-responsive dystonia
- Segawa syndrome, autosomal recessive
- Tyrosine hydroxylase deficiency
- Dopa-responsive dystonia