SMOX

Polyamines are ubiquitous polycationic alkylamines which include spermine, spermidine, putrescine, and agmatine. These molecules participate in a broad range of cellular functions which include cell cycle modulation, scavenging reactive oxygen species, and the control of gene expression. These molecules also play important roles in neurotransmission through their regulation of cell-surface receptor activity, involvement in intracellular signalling pathways, and their putative roles as neurotransmitters. This gene encodes an FAD-containing enzyme that catalyzes the oxidation of spermine to spermadine and secondarily produces hydrogen peroxide. Multiple transcript variants encoding different isoenzymes have been identified for this gene, some of which have failed to demonstrate significant oxidase activity on natural polyamine substrates. The characterized isoenzymes have distinctive biochemical characteristics and substrate specificities, suggesting the existence of additional levels of complexity in polyamine catabolism.

Full Name

Spermine Oxidase

Function

Flavoenzyme which catalyzes the oxidation of spermine to spermidine. Can also use N1-acetylspermine and spermidine as substrates, with different affinity depending on the isoform (isozyme) and on the experimental conditions. Plays an important role in the regulation of polyamine intracellular concentration and has the potential to act as a determinant of cellular sensitivity to the antitumor polyamine analogs. May contribute to beta-alanine production via aldehyde dehydrogenase conversion of 3-amino-propanal.

Biological Process

Biological Process polyamine biosynthetic processTAS:Reactome
Biological Process polyamine catabolic processManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process spermine catabolic processIDA:UniProtKB
Biological Process xenobiotic metabolic processTAS:Reactome

Cellular Location

Isoform 1
Cytoplasm
Nucleus
Isoform 4
Cytoplasm
Nucleus
Isoform 6
Cytoplasm
Nucleus