Beta-ureidopropionase 1 (UPB1)

Beta-ureidopropionase 1 (UPB1) is an enzyme encoded by the UPB1 gene, part of the CN hydrolase family and the nitrilase superfamily[6][3][5]. It catalyzes the final step in the breakdown of pyrimidines, converting N-carbamyl-beta-aminoisobutyric acid to beta-aminoisobutyric acid and N-carbamyl-beta-alanine to beta-alanine, ammonia, and carbon dioxide[1][2][6][5]. These products have neurological roles, including modulating synaptic transmission and affecting dopamine levels, while beta-aminoisobutyric acid is linked to leptin production and neuroprotection[1][2]. Genetic deficiencies of UPB1 lead to metabolic accumulation, neurological symptoms, and increased susceptibility to 5-fluorouracil toxicity because UPB1 helps metabolize this chemotherapeutic agent[3]. Disease states related to UPB1 are autosomal recessive, with variable clinical severity, and diagnostic markers include abnormal urinary concentrations of pyrimidine catabolites[1][2][3][6].

Other names

Beta-ureidopropionaseBUP1Beta-alanine synthaseN-carbamoyl-beta-alanine amidohydrolaseUreidopropionase beta

Drugs metabolized by the pyrimidine degradation pathway (not directly targeted, but UPB1 dysfunction alters drug clearance and toxicity of agents like 5-fluorouracil)