Urea cycle and metabolism of amino groups (WP497)
Homo sapiens
The urea cycle (also known as the ornithine cycle) is a cycle of biochemical reactions that produces urea ((NH2)2CO) from ammonia (NH3). This cycle occurs in ureotelic organisms. The urea cycle converts highly toxic ammonia to urea for excretion. This cycle was the first metabolic cycle to be discovered (Hans Krebs and Kurt Henseleit, 1932), five years before the discovery of the TCA cycle. The urea cycle takes place primarily in the liver and, to a lesser extent, in the kidneys. Amino acid catabolism results in waste ammonia. All animals need a way to excrete this product. Most aquatic organisms, or ammonotelic organisms, excrete ammonia without converting it. Ammonia is toxic, but upon excretion from aquatic species, it is diluted by the water outside the organism. Organisms that cannot easily and safely remove nitrogen as ammonia convert it to a less toxic substance such as urea or uric acid. The urea cycle mainly occurs in the liver. The urea produced by the liver is then released into the bloodstream where it travels to the kidneys and is ultimately excreted in urine. In species including birds and most insects, the ammonia is converted into uric acid or its urate salt, which is excreted in solid form. Source description: [https://en.wikipedia.org/wiki/Urea_cycle Wikipedia] Proteins on this pathway have targeted assays available via the [https://assays.cancer.gov/available_assays?wp_id=WP497 CPTAC Assay Portal].
Authors
Lynn M. Ferrante , Thomas Kelder , Kristina Hanspers , Adrien Defay , Martina Summer-Kutmon , Egon Willighagen , Denise Slenter , Irene Hemel , and Finterly HuActivity
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Cited In
- Heterogeneity of Lipid and Protein Cartilage Profiles Associated with Human Osteoarthritis with or without Type 2 Diabetes Mellitus (2021).
- Reconstructed Human Skin with Hypodermis Shows Essential Role of Adipose Tissue in Skin Metabolism (2024).
- Integrative epigenetic profiling analysis identifies DNA methylation changes associated with chronic alcohol consumption (2015).
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Organisms
Homo sapiensCommunities
Annotations
Pathway Ontology
urea cycle pathway| Label | Type | Compact URI | Comment |
|---|---|---|---|
| L-Glutamate | Metabolite | cas:56-86-0 | L-Glutamate |
| L-Glutamate 5-semialdehyde | Metabolite | kegg.compound:C01165 | tautomer of (S)-1-Pyrroline-5-carboxylate |
| Phosphoguanidinoacetate | Metabolite | kegg.compound:C03166 | |
| L-Aspartate | Metabolite | kegg.compound:C00049 | |
| NH3 | Metabolite | kegg.compound:C00014 | |
| Urea | Metabolite | cas:57-13-6 | Urea |
| Putrescine | Metabolite | cas:110-60-1 | Putrescine |
| L-Ornithine | Metabolite | cas:70-26-8 | L-Ornithine |
| Urea-1-carboxylate | Metabolite | kegg.compound:C01010 | |
| N-(L-Arginino)succinate | Metabolite | kegg.compound:C03406 | |
| Creatine | Metabolite | cas:57-00-1 | Creatine |
| L-Proline | Metabolite | cas:147-85-3 | L-Proline |
| L-glutamyl | Metabolite | chebi:29972 | |
| L-Citrulline | Metabolite | cas:372-75-8 | L-Citrulline |
| Arginine | Metabolite | cas:74-79-3 | L-Arginine |
| Guanidinoacetate | Metabolite | kegg.compound:C00581 | |
| N2-Acetyl-L-ornithine | Metabolite | kegg.compound:C00437 | |
| Formaldehyde | Metabolite | cas:50-00-0 | Formaldehyde |
| Sarcosine | Metabolite | cas:107-97-1 | Sarcosine |
| Spermidine | Metabolite | cas:124-20-9 | Spermidine |
| N-Acetyl-L-glutamate | Metabolite | kegg.compound:C00624 | |
| Spermine | Metabolite | cas:71-44-3 | Spermine |
| Creatinine | Metabolite | cas:60-27-5 | Creatinine |
| Carbamoyl | Metabolite | kegg.compound:C00169 | |
| N-Methylhydantoin | Metabolite | kegg.compound:C02565 | |
| Formate | Metabolite | kegg.compound:C00058 | |
| creatine-P | Metabolite | cas:67-07-2 | Phosphocreatine |
| N-Acetyl-glutamate | Metabolite | kegg.compound:C00624 | |
| N-Carbamoylsarcosine | Metabolite | kegg.compound:C01043 | |
| CO2 | Metabolite | kegg.compound:C00011 | |
| (S)-1-Pyrroline-5-carboxylate | Metabolite | kegg.compound:C03912 | Tautomer of L-glutamate 5-semialdehyde |
| Fumarate | Metabolite | kegg.compound:C00122 | |
| 3.5.1.5 | GeneProduct | eccode:3.5.1.5 | |
| GAMT | Protein | uniprot:Q14353 | |
| SARDH | Protein | uniprot:Q9UL12 | |
| CKB | Protein | uniprot:P12277 | |
| 6.3.4.6 | Protein | eccode:6.3.4.6 | |
| ODC1 | Protein | uniprot:P11926 | |
| CPS1 | Protein | uniprot:P31327 | |
| 2.7.3.1 | Protein | eccode:2.7.3.1 | |
| 1.2.1.46 | Protein | eccode:1.2.1.46 | |
| CKM | Protein | uniprot:P06732 | |
| SRM | Protein | uniprot:P19623 | |
| 2.3.1.35 | Protein | eccode:2.3.1.35 | |
| PYCRL | Protein | uniprot:Q53H96 | |
| GLUD1 | Protein | uniprot:P00367 | |
| SMS | Protein | uniprot:P52788 | |
| 3.5.4.21 | Protein | eccode:3.5.4.21 | |
| 1.2.1.38 | Protein | eccode:1.2.1.38 | |
| 2.7.2.8 | Protein | eccode:2.7.2.8 | |
| 2.6.1.69 | Protein | eccode:2.6.1.69 | |
| ARG1 | Protein | uniprot:P05089 | |
| ARG2 | Protein | uniprot:P78540 | |
| OAT | Protein | uniprot:P04181 | |
| ALDH18A1 | Protein | uniprot:P54886 | |
| GATM | Protein | uniprot:P50440 | |
| 2.6.1.11 | Protein | eccode:2.6.1.11 | |
| ASS | Protein | uniprot:P00966 | |
| PYCR1 | Protein | uniprot:P32322 | |
| ASL | Protein | uniprot:P04424 | |
| NAGS | Protein | uniprot:Q8N159 | |
| OTC | Protein | uniprot:P00480 | |
| 3.5.3.3 | Protein | eccode:3.5.3.3 | |
| 3.5.2.10 | Protein | eccode:3.5.2.10 | |
| 3.5.2.14 | Protein | eccode:3.5.2.14 | |
| 3.5.1.54 | Protein | eccode:3.5.1.54 | |
| 3.5.1.16 | Protein | eccode:3.5.1.16 | |
| 3.5.1.59 | Protein | eccode:3.5.1.59 | |
| ACY1 | Protein | uniprot:Q03154 |
References
-
Possible Mechanisms for Adverse Effects of
L -Canavanine on Insects. Dahlman DL, Berge MA. In: Natural Resistance of Plants to Pests [Internet]. American Chemical Society; 1986. p. 118–29. Available from: http://dx.doi.org/10.1021/bk-1986-0296.ch010 DOI Scholia - Ornithine aminotransferase, a potential target for the treatment of hyperammonemias. Seiler N. Curr Drug Targets. 2000 Sep;1(2):119–53. PubMed Europe PMC Scholia
- A nuclear gene encoding mitochondrial Delta-pyrroline-5-carboxylate dehydrogenase and its potential role in protection from proline toxicity. Deuschle K, Funck D, Hellmann H, Däschner K, Binder S, Frommer WB. Plant J. 2001 Aug;27(4):345–56. PubMed Europe PMC Scholia