Harmonizome 3.0

ornithine carbamoyltransferase

This nuclear gene encodes a mitochondrial matrix enzyme. The encoded protein is involved in the urea cycle which functions to detoxify ammonia into urea for excretion. Mutations in this enzyme lead to ornithine transcarbamylase deficiency, which causes hyperammonemia. [provided by RefSeq, May 2022]

ornithine decarboxylase 1

This gene encodes the rate-limiting enzyme of the polyamine biosynthesis pathway which catalyzes ornithine to putrescine. The activity level for the enzyme varies in response to growth-promoting stimuli and exhibits a high turnover rate in comparison to other mammalian proteins. Originally localized to both chromosomes 2 and 7, the gene encoding this enzyme has been determined to be located on 2p25, with a pseudogene located on 7q31-qter. Multiple alternatively spliced transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, Dec 2013]

ornithine decarboxylase pseudogene

ornithine aminotransferase pseudogene

ornithine decarboxylase antizyme 2

The protein encoded by this gene belongs to the ornithine decarboxylase antizyme family, which plays a role in cell growth and proliferation by regulating intracellular polyamines. Expression of antizymes requires +1 ribosomal frameshifting, which is enhanced by high levels of polyamines. Antizymes in turn bind to and inhibit ornithine decarboxylase (ODC), the key enzyme in polyamine biosynthesis; thus, completing the auto-regulatory circuit. This gene encodes antizyme 2, the second member of the antizyme family. Like antizyme 1, antizyme 2 has broad tissue distribution, inhibits ODC activity and polyamine uptake, and stimulates ODC degradation in vivo; however, it fails to promote ODC degradation in vitro. Antizyme 2 is expressed at lower levels than antizyme 1, but is evolutionary more conserved, suggesting it likely has an important biological role. Studies also show different subcellular localization of antizymes 1 and 2, indicating specific function for each antizyme in discrete compartments of the cell. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Dec 2014]

ornithine decarboxylase antizyme 3

The protein encoded by this gene belongs to the ornithine decarboxylase antizyme family, which plays a role in cell growth and proliferation by regulating intracellular polyamine levels. Expression of antizymes requires +1 ribosomal frameshifting, which is enhanced by high levels of polyamines. Antizymes in turn bind to and inhibit ornithine decarboxylase (ODC), the key enzyme in polyamine biosynthesis; thus, completing the auto-regulatory circuit. This gene encodes antizyme 3, the third member of the antizyme family. Like antizymes 1 and 2, antizyme 3 inhibits ODC activity and polyamine uptake; however, it does not stimulate ODC degradation. Also, while antizymes 1 and 2 have broad tissue distribution, expression of antizyme 3 is restricted to haploid germ cells in testis, suggesting a distinct role for this antizyme in spermiogenesis. Antizyme 3 gene knockout studies showed that homozygous mutant male mice were infertile, and indicated the likely role of this antizyme in the formation of a rigid connection between the sperm head and tail during spermatogenesis. Alternatively spliced transcript variants encoding different isoforms, including one resulting from the use of non-AUG (CUG) translation initiation codon, have been found for this gene. [provided by RefSeq, Dec 2014]

ornithine decarboxylase antizyme 1

The protein encoded by this gene belongs to the ornithine decarboxylase antizyme family, which plays a role in cell growth and proliferation by regulating intracellular polyamine levels. Expression of antizymes requires +1 ribosomal frameshifting, which is enhanced by high levels of polyamines. Antizymes in turn bind to and inhibit ornithine decarboxylase (ODC), the key enzyme in polyamine biosynthesis; thus, completing the auto-regulatory circuit. This gene encodes antizyme 1, the first member of the antizyme family, that has broad tissue distribution, and negatively regulates intracellular polyamine levels by binding to and targeting ODC for degradation, as well as inhibiting polyamine uptake. Antizyme 1 mRNA contains two potential in-frame AUGs; and studies in rat suggest that alternative use of the two translation initiation sites results in N-terminally distinct protein isoforms with different subcellular localization. Alternatively spliced transcript variants have also been noted for this gene. [provided by RefSeq, Dec 2014]

ornithine aminotransferase pseudogene

ornithine aminotransferase pseudogene

ornithine aminotransferase pseudogene

ornithine aminotransferase pseudogene 1

ornithine aminotransferase pseudogene

ornithine aminotransferase pseudogene

ornithine aminotransferase pseudogene

ornithine aminotransferase, mitochondrial-like

ornithine aminotransferase pseudogene

solute carrier family 25 (mitochondrial carrier; ornithine transporter) member 15 pseudogene 1

solute carrier family 25 (mitochondrial carrier; ornithine transporter) member 15 pseudogene 2

solute carrier family 25 (mitochondrial carrier; ornithine transporter) member 15 pseudogene 3

solute carrier family 25 (mitochondrial carrier; ornithine transporter) member 15 pseudogene 5

ornithine aminotransferase pseudogene

ornithine aminotransferase pseudogene

ornithine aminotransferase pseudogene

ornithine aminotransferase pseudogene

ornithine decarboxylase antizyme 1 pseudogene

solute carrier family 25 (mitochondrial carrier; ornithine transporter) member 15 pseudogene 4

solute carrier family 25 (mitochondrial carrier; ornithine transporter) member 15

This gene is a member of the mitochondrial carrier family. The encoded protein transports ornithine across the inner mitochondrial membrane from the cytosol to the mitochondrial matrix. The protein is an essential component of the urea cycle, and functions in ammonium detoxification and biosynthesis of the amino acid arginine. Mutations in this gene result in hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome. There is a pseudogene of this locus on the Y chromosome.[provided by RefSeq, May 2009]

ornithine aminotransferase

This gene encodes the mitochondrial enzyme ornithine aminotransferase, which is a key enzyme in the pathway that converts arginine and ornithine into the major excitatory and inhibitory neurotransmitters glutamate and GABA. Mutations that result in a deficiency of this enzyme cause the autosomal recessive eye disease Gyrate Atrophy. Alternatively spliced transcript variants encoding different isoforms have been described. Related pseudogenes have been defined on the X chromosome. [provided by RefSeq, Jan 2010]

solute carrier family 25 (mitochondrial carrier; ornithine transporter) member 2

This intronless gene encodes a protein that localizes to the mitochondrial inner membrane and likely functions as a transporter of small molecules such as ornithine. This gene is located between the protocadherin beta and gamma gene clusters on chromosome 5. [provided by RefSeq, Dec 2014]