Cyclohydrolase 1 (GTP) Antibody – Rabbit Polyclonal

GCH1: Positively regulates nitric oxide synthesis in umbilical vein endothelial cells (HUVECs). May be involved in dopamine synthesis. May modify pain sensitivity and persistence. Isoform GCH-1 is the functional enzyme, the potential function of the enzymatically inactive isoforms remains unknown. Defects in GCH1 are the cause of GTP cyclohydrolase 1 deficiency (GCH1D); also known as atypical severe phenylketonuria due to GTP cyclohydrolase I deficiency;. GCH1D is one of the causes of malignant hyperphenylalaninemia due to tetrahydrobiopterin deficiency. It is also responsible for defective neurotransmission due to depletion of the neurotransmitters dopamine and serotonin. The principal symptoms include: psychomotor retardation, tonicity disorders, convulsions, drowsiness, irritability, abnormal movements, hyperthermia, hypersalivation, and difficulty swallowing. Some patients may present a phenotype of intermediate severity between severe hyperphenylalaninemia and mild dystonia type 5 (dystonia- parkinsonism with diurnal fluctuation). In this intermediate phenotype, there is marked motor delay, but no mental retardation and only minimal, if any, hyperphenylalaninemia. Defects in GCH1 are the cause of dystonia type 5 (DYT5); also known as progressive dystonia with diurnal fluctuation, autosomal dominant Segawa syndrome or dystonia- parkinsonism with diurnal fluctuation. DYT5 is a DOPA-responsive dystonia. Dystonia is defined by the presence of sustained involuntary muscle contractions, often leading to abnormal postures. DYT5 typically presents in childhood with walking problems due to dystonia of the lower limbs and worsening of the dystonia towards the evening. It is characterized by postural and motor disturbances showing marked diurnal fluctuation. Torsion of the trunk is unusual. Symptoms are alleviated after sleep and aggravated by fatigue and excercise. There is a favorable response to L-DOPA without side effects. Belongs to the GTP cyclohydrolase I family. 4 isoforms of the human protein are produced by alternative splicing.

Protein type: EC 3.5.4.16; Cofactor and Vitamin Metabolism - folate biosynthesis; Hydrolase

Cellular Component: cytoplasm; cytoplasmic vesicle; cytosol; nuclear membrane; nucleoplasm; nucleus; protein complex

Molecular Function: calcium ion binding; catalytic activity; coenzyme binding; GTP binding; GTP cyclohydrolase I activity; GTP-dependent protein binding; hydrolase activity; metal ion binding; nucleotide binding; protein homodimerization activity; translation initiation factor binding; zinc ion binding

Biological Process: dihydrobiopterin metabolic process; dopamine biosynthetic process; metabolic process; negative regulation of blood pressure; neuromuscular process controlling posture; positive regulation of nitric-oxide synthase activity; protein complex assembly; protein heterooligomerization; protein homooligomerization; pteridine and derivative biosynthetic process; regulation of blood pressure; regulation of lung blood pressure; response to pain; tetrahydrobiopterin biosynthetic process; tetrahydrofolate biosynthetic process; vasodilation