AZIN1

Ornithine decarboxylase (ODC) catalyzes the conversion of ornithine to putrescine in the first and apparently rate-limiting step in polyamine biosynthesis. Ornithine decarboxylase antizymes play a role in the regulation of polyamine synthesis by binding to and inhibiting ornithine decarboxylase. The protein encoded by this gene is highly similar to ODC. It binds to ODC antizyme and stabilizes ODC, thus inhibiting antizyme-mediated ODC degradation. Two alternatively spliced transcript variants have been found for this gene. [provided by RefSeq]

Full Name

antizyme inhibitor 1

Function

Antizyme inhibitor (AZI) protein that positively regulates ornithine decarboxylase (ODC) activity and polyamine uptake. AZI is an enzymatically inactive ODC homolog that counteracts the negative effect of ODC antizymes (AZs) OAZ1, OAZ2 and OAZ3 on ODC activity by competing with ODC for antizyme-binding (PubMed:17900240, PubMed:26305948).
Inhibits antizyme-dependent ODC degradation and releases ODC monomers from their inactive complex with antizymes, leading to formation of the catalytically active ODC homodimer and restoring polyamine production (PubMed:17900240).

Biological Process

Negative regulation of protein catabolic process Source: UniProtKB
Positive regulation of polyamine transmembrane transport Source: UniProtKB
Putrescine biosynthetic process from ornithine Source: GO_Central
Regulation of cellular amino acid metabolic process Source: Reactome

Cellular Location

Nucleus

PTM

Ubiquitinated, leading to its proteasomal degradation; a process that is reduced in presence of antizyme OAZ1.