HAAO

3-Hydroxyanthranilate 3,4-dioxygenase is a monomeric cytosolic protein belonging to the family of intramolecular dioxygenases containing nonheme ferrous iron. It is widely distributed in peripheral organs, such as liver and kidney, and is also present in low amounts in the central nervous system. HAAO catalyzes the synthesis of quinolinic acid (QUIN) from 3-hydroxyanthranilic acid. QUIN is an excitotoxin whose toxicity is mediated by its ability to activate glutamate N-methyl-D-aspartate receptors. Increased cerebral levels of QUIN may participate in the pathogenesis of neurologic and inflammatory disorders. HAAO has been suggested to play a role in disorders associated with altered tissue levels of QUIN. [provided by RefSeq]

Full Name

3-hydroxyanthranilate 3,4-dioxygenase

Function

Catalyzes the oxidative ring opening of 3-hydroxyanthranilate to 2-amino-3-carboxymuconate semialdehyde, which spontaneously cyclizes to quinolinate.

Biological Process

de novo' NAD biosynthetic process from tryptophan Source: GO_Central
Anthranilate metabolic process Source: UniProtKB-UniRule
NAD biosynthetic process Source: UniProtKB
Neuron cellular homeostasis Source: UniProtKB
Quinolinate biosynthetic process Source: UniProtKB
Quinolinate metabolic process Source: GO_Central
Response to cadmium ion Source: UniProtKB
Response to zinc ion Source: UniProtKB
Tryptophan catabolic process Source: UniProtKB-UniRule

Cellular Location

Cytosol

Involvement in disease

Vertebral, cardiac, renal, and limb defects syndrome 1 (VCRL1):
An autosomal recessive congenital malformation syndrome characterized by vertebral segmentation abnormalities, congenital cardiac defects, renal defects, and distal mild limb defects.