CPS1: Involved in the urea cycle of ureotelic animals where the enzyme plays an important role in removing excess ammonia from the cell. Defects in CPS1 are the cause of carbamoyl phosphate synthetase 1 deficiency (CPS1D). CPS1D is an autosomal recessive disorder of the urea cycle causing hyperammonemia. Clinical features include protein intolerance, intermittent ataxia, seizures, lethargy, developmental delay and mental retardation. Genetic variations in CPS1 influence the availability of precursors for nitric oxide (NO) synthesis and play a role in clinical situations where endogenous NO production is critically important, such as neonatal pulmonary hypertension, increased pulmonary artery pressure following surgical repair of congenital heart defects or hepatovenocclusive disease following bone marrow transplantation. Infants with neonatal pulmonary hypertension homozygous for Thr-1406 have lower L-arginine concentrations than neonates homozygous for Asn-1406. 2 isoforms of the human protein are produced by alternative splicing.
Protein type: EC 6.3.4.16; Amino Acid Metabolism - alanine, aspartate and glutamate; Ligase; Energy Metabolism - nitrogen; Amino Acid Metabolism - arginine and proline; Mitochondrial; Nucleolus
Chromosomal Location of Human Ortholog: 2q35
Cellular Component: mitochondrial inner membrane; mitochondrial matrix; nucleolus; protein complex
Molecular Function: aspartate carbamoyltransferase activity; ATP binding; calcium ion binding; carbamoyl-phosphate synthase (ammonia) activity; carbamoyl-phosphate synthase (glutamine-hydrolyzing) activity; dihydroorotase activity; endopeptidase activity; glutamate binding; phospholipid binding; protein binding; protein complex binding
Biological Process: 'de novo' pyrimidine base biosynthetic process; anion homeostasis; arginine biosynthetic process; citrulline biosynthetic process; glutamine metabolic process; glycogen catabolic process; homocysteine metabolic process; midgut development; nitric oxide metabolic process; positive regulation of vasodilation; proteolysis; response to amine stimulus; response to amino acid stimulus; response to drug; response to food; response to lipopolysaccharide; response to starvation; response to toxin; response to zinc ion; triacylglycerol catabolic process; urea cycle
Disease: Carbamoyl Phosphate Synthetase I Deficiency, Hyperammonemia Due To; Pulmonary Hypertension, Neonatal, Susceptibility To
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