Catalyzes the hydrolytic deamination of adenosine and 2-deoxyadenosine (PubMed:16670267, PubMed:23193172, PubMed:26166670, PubMed:8452534, PubMed:9361033). Plays an important role in purine metabolism and in adenosine homeostasis. Modulates signaling by extracellular adenosine, and so contributes indirectly to cellular signaling events. Acts as a positive regulator of T-cell coactivation, by binding DPP4 (PubMed:20959412). Its interaction with DPP4 regulates lymphocyte-epithelial cell adhesion (

Cell membraneCell junctionCytoplasmic vesicle lumenCytoplasmLysosome

Severe combined immunodeficiency autosomal recessive T-cell-negative/B-cell-negative/NK-cell-negative due to adenosine deaminase deficiency

An autosomal recessive disorder accounting for about 50% of non-X-linked SCIDs. SCID refers to a genetically and clinically heterogeneous group of rare congenital disorders characterized by impairment of both humoral and cell-mediated immunity, leukopenia, and low or absent antibody levels. Patients with SCID present in infancy with recurrent, persistent infections by opportunistic organisms. The common characteristic of all types of SCID is absence of T-cell-mediated cellular immunity due to a defect in T-cell development. ADA deficiency has been diagnosed in chronically ill teenagers and adults (late or adult onset). Population and newborn screening programs have also identified several healthy individuals with normal immunity who have partial ADA deficiency.

AMP deaminase plays a critical role in energy metabolism

Myopathy due to myoadenylate deaminase deficiency

A metabolic disorder resulting in exercise-related myopathy. It is characterized by exercise-induced muscle aches, cramps, and early fatigue.

AMP deaminase plays a critical role in energy metabolism

Adenosine monophosphate deaminase deficiency erythrocyte type

A metabolic disorder due to lack of activity of the erythrocyte isoform of AMP deaminase. It is a clinically asymptomatic condition characterized by a 50% increase in steady-state levels of ATP in affected cells. Individuals with complete deficiency of erythrocyte AMP deaminase are healthy and have no hematologic disorders.

Catalyzes two non-sequential steps in de novo AMP synthesis: converts (S)-2-(5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamido)succinate (SAICAR) to fumarate plus 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide, and thereby also contributes to de novo IMP synthesis, and converts succinyladenosine monophosphate (SAMP) to AMP and fumarate

Adenylosuccinase deficiency

An autosomal recessive disorder characterized by the accumulation in the body fluids of succinylaminoimidazole-carboxamide riboside (SAICA-riboside) and succinyladenosine (S-Ado). Most children display marked psychomotor delay, often accompanied by epilepsy or autistic features, or both, although some patients may be less profoundly retarded. Occasionally, growth retardation and muscular wasting are also present.

Bifunctional enzyme that catalyzes the last two steps of purine biosynthesis (PubMed:11948179, PubMed:14756554). Acts as a transformylase that incorporates a formyl group to the AMP analog AICAR (5-amino-1-(5-phospho-beta-D-ribosyl)imidazole-4-carboxamide) to produce the intermediate formyl-AICAR (FAICAR) (PubMed:10985775, PubMed:11948179, PubMed:9378707). Can use both 10-formyldihydrofolate and 10-formyltetrahydrofolate as the formyl donor in this reaction (PubMed:10985775). Also catalyzes the

Cytoplasm, cytosol

AICA-ribosuria due to ATIC deficiency

A neurologically devastating inborn error of purine biosynthesis. Patients excrete massive amounts of AICA-riboside in the urine and accumulate AICA-ribotide and its derivatives in erythrocytes and fibroblasts. Clinical features include profound intellectual disability, epilepsy, dysmorphic features and congenital blindness. AICAR inheritance is autosomal recessive.

Hormone secreted by pancreatic cells that acts as a regulator of pancreatic and gastrointestinal functions probably by signaling through the G protein-coupled receptor NPY4R2

Secreted

Transcriptional activator or repressor which serves as a general switch factor for erythroid development (PubMed:35030251). It binds to DNA sites with the consensus sequence 5'-[AT]GATA[AG]-3' within regulatory regions of globin genes and of other genes expressed in erythroid cells. Activates the transcription of genes involved in erythroid differentiation of K562 erythroleukemia cells, including HBB, HBG1/2, ALAS2 and HMBS (PubMed:24245781)

Nucleus

X-linked dyserythropoietic anemia and thrombocytopenia

Disorder characterized by erythrocytes with abnormal size and shape, and paucity of platelets in peripheral blood. The bone marrow contains abundant and abnormally small megakaryocytes.

Catalyzes a salvage reaction resulting in the formation of AMP, that is energically less costly than de novo synthesis

Cytoplasm

Adenine phosphoribosyltransferase deficiency

An enzymatic deficiency that can lead to urolithiasis and renal failure. Patients have 2,8-dihydroxyadenine (DHA) urinary stones.

Sulfurates the molybdenum cofactor (PubMed:34356852). Sulfation of molybdenum is essential for xanthine dehydrogenase (XDH) and aldehyde oxidase (ADO) enzymes in which molybdenum cofactor is liganded by 1 oxygen and 1 sulfur atom in active form (PubMed:34356852). In vitro, the C-terminal domain is able to reduce N-hydroxylated prodrugs, such as benzamidoxime (PubMed:16973608)

Xanthinuria 2

A disorder characterized by excretion of very large amounts of xanthine in the urine and a tendency to form xanthine stones. Uric acid is strikingly diminished in serum and urine. In addition, XAN2 patients cannot metabolize allopurinol into oxypurinol due to dual deficiency of xanthine dehydrogenase and aldehyde oxidase.

Functions in biogenesis and organization of the apical membrane of epithelial cells of the thick ascending limb of Henle's loop (TALH), where it promotes formation of complex filamentous gel-like structure that may play a role in the water barrier permeability (Probable). May serve as a receptor for binding and endocytosis of cytokines (IL-1, IL-2) and TNF (PubMed:3498215). Facilitates neutrophil migration across renal epithelia (PubMed:20798515) In the urine, may contribute to colloid osmotic p

Apical cell membraneBasolateral cell membraneCell projection, cilium membraneSecreted

Tubulointerstitial kidney disease, autosomal dominant 1

A form of autosomal dominant tubulointerstitial kidney disease, a genetically heterogeneous disorder characterized by slowly progressive loss of kidney function, bland urinary sediment, hyperuricemia, absent or mildly increased albuminuria, lack of severe hypertension during the early stages, and normal or small kidneys on ultrasound. Renal histology shows variable abnormalities including interstitial fibrosis with tubular atrophy, microcystic dilatation of the tubules, thickening of tubular basement membranes, medullary cysts, and secondary glomerulosclerotic or glomerulocystic changes with abnormal glomerular tufting. There is significant variability, as well as incomplete penetrance.

Converts guanine to guanosine monophosphate, and hypoxanthine to inosine monophosphate. Transfers the 5-phosphoribosyl group from 5-phosphoribosylpyrophosphate onto the purine. Plays a central role in the generation of purine nucleotides through the purine salvage pathway

Cytoplasm

Lesch-Nyhan syndrome

Characterized by complete lack of enzymatic activity that results in hyperuricemia, choreoathetosis, intellectual disability, and compulsive self-mutilation.

Pyrophosphatase that hydrolyzes the non-canonical purine nucleotides inosine triphosphate (ITP), deoxyinosine triphosphate (dITP) as well as 2'-deoxy-N-6-hydroxylaminopurine triphosphate (dHAPTP) and xanthosine 5'-triphosphate (XTP) to their respective monophosphate derivatives. The enzyme does not distinguish between the deoxy- and ribose forms. Probably excludes non-canonical purines from RNA and DNA precursor pools, thus preventing their incorporation into RNA and DNA and avoiding chromosomal

Cytoplasm

Inosine triphosphate pyrophosphohydrolase deficiency

A common inherited condition characterized by the abnormal accumulation of inosine triphosphate in erythrocytes. It might have pharmacogenomic implications and be related to increased drug toxicity of purine analog drugs.

Catalyzes the synthesis of phosphoribosylpyrophosphate (PRPP) that is essential for nucleotide synthesis

Phosphorylates deoxyguanosine and deoxyadenosine in the mitochondrial matrix, with the highest efficiency for deoxyguanosine (PubMed:11687801, PubMed:17073823, PubMed:23043144, PubMed:8692979, PubMed:8706825). In non-replicating cells, where cytosolic dNTP synthesis is down-regulated, mtDNA synthesis depends solely on DGUOK and TK2. Phosphorylates certain nucleoside analogs (By similarity). Widely used as target of antiviral and chemotherapeutic agents

Mitochondrion

Mitochondrial DNA depletion syndrome 3

A disorder due to mitochondrial dysfunction characterized by onset in infancy of progressive liver failure, hypoglycemia, increased lactate in body fluids, and neurologic abnormalities including hypotonia, encephalopathy, peripheral neuropathy. Affected tissues show both decreased activity of the mtDNA-encoded respiratory chain complexes and mtDNA depletion.

Key enzyme in purine degradation. Catalyzes the oxidation of hypoxanthine to xanthine. Catalyzes the oxidation of xanthine to uric acid. Contributes to the generation of reactive oxygen species. Has also low oxidase activity towards aldehydes (in vitro)

CytoplasmPeroxisomeSecreted

Xanthinuria 1

A disorder characterized by excretion of very large amounts of xanthine in the urine and a tendency to form xanthine stones. Uric acid is strikingly diminished in serum and urine. XAN1 is due to isolated xanthine dehydrogenase deficiency. Patients can metabolize allopurinol.