AZIN2
AZIN2 (antizyme inhibitor 2, also known as ODC-p, ODC1L, KIAA1945 and formerly arginine decarboxylase) is an enzymatically inactive homologue of ornithine decarboxylase. It positively regulates polyamine levels by sequestering antizymes and also contributes to secretory vesicle trafficking. Browse Assay Genie's current range of AZIN2 research reagents below, or read on for the biology behind the target.
AZIN2 is an antizyme inhibitor that positively regulates ornithine decarboxylase (ODC) activity and polyamine uptake. It is an ODC homologue that has lost the ability to decarboxylase ornithine but retains the ability to bind antizymes. Antizymes (OAZ1, OAZ2 and OAZ3) restrain polyamine levels by binding ODC and targeting it for degradation, and by inhibiting polyamine uptake. AZIN2 competes with ODC for antizyme binding, inhibits antizyme-dependent ODC degradation and releases ODC monomers from their inactive complex with antizymes. This allows the catalytically active ODC homodimer to form and restores polyamine production. Through this mechanism the antizyme inhibitor family supports cell growth and proliferation by maintaining polyamine homeostasis.
The AZIN2 gene encodes the second member of the antizyme inhibitor family and belongs to the Orn/Lys/Arg decarboxylase class-II family. Like antizyme inhibitor 1, it interacts with all three antizymes and stimulates ODC activity and polyamine uptake. Unlike antizyme inhibitor 1, which is ubiquitously expressed in the nucleus and cytoplasm, AZIN2 is predominantly expressed in the brain and testis and localises to the endoplasmic reticulum-Golgi intermediate compartment. It has also been reported in specific cell types of the ovary, adrenal gland and pancreas, and in mast cells. Alternatively spliced transcript variants have been described. Mouse and rat orthologs are both named Azin2.
AZIN2 also participates in the morphological integrity of the trans-Golgi network and regulates intracellular secretory vesicle trafficking. Available data suggest roles in cell growth, spermiogenesis, vesicular trafficking and secretion, although its exact function is not known. Accumulation of AZIN2 has been observed in the brains of patients with Alzheimer's disease. The gene was formerly called arginine decarboxylase after a report of ADC activity for a cDNA clone identical to ODCp/AZIN2. Later studies in human and mouse showed that AZIN2 has no arginine decarboxylase activity.
AZIN2 counteracts antizymes to maintain ODC activity and polyamine uptake, making it a useful node for studying polyamine homeostasis.
AZIN2 contributes to trans-Golgi network integrity and regulates secretory vesicle trafficking, relevant to studies of vesicular transport and secretion.
AZIN2 is predominantly expressed in brain and accumulates in the brains of patients with Alzheimer's disease.
AZIN2 is highly expressed in testis, and available data suggest a role in spermiogenesis.
AZIN2 is an enzymatically inactive ODC homologue that binds antizymes OAZ1, OAZ2 and OAZ3, competing with ODC for antizyme binding. This protects ODC from antizyme-dependent degradation, restores active ODC homodimers and polyamine production, and stimulates polyamine uptake. It also regulates secretory vesicle trafficking.
ODC-p (ODCp) and ODC1L reflect its similarity to ornithine decarboxylase. The name arginine decarboxylase (ADC) came from an early report of such activity for an identical cDNA clone, but later human and mouse studies found AZIN2 devoid of arginine decarboxylase activity. KIAA1945 is another alias.
Both interact with all three antizymes and stimulate ODC activity and polyamine uptake. Antizyme inhibitor 1 is ubiquitously expressed in the nucleus and cytoplasm, whereas AZIN2 is predominantly found in brain and testis and localises to the ER-Golgi intermediate compartment. Mouse and rat Azin2 orthologs exist; check the datasheet of any product for its validated reactivity.
Other antizyme inhibitors, antizymes and polyamine biosynthesis proteins with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q96A70; product specifications from Assay Genie datasheets.