Reactome | ornithine (cytosolic) + citrulline (mitochondrial) => ornithine (mitochondrial) + citrulline (cytosolic)

ornithine (cytosolic) + citrulline (mitochondrial) => ornithine (mitochondrial) + citrulline (cytosolic)

Stable Identifier

R-HSA-70634

Type

Reaction [transition]

Species

Homo sapiens

Compartment

cytosol, mitochondrial inner membrane, mitochondrial matrix

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ornithine (cytosolic) + citrulline (mitochondrial) => ornithine (mitochondrial) + citrulline (cytosolic)

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The mitochondrial ornithine transporters SLC25A15 and SLC25A2 mediate the exchange of cytosolic ornithine for citrulline from the mitochondrial matrix. SLC25A15 was the first protein shown to have this function, identified because mutations in the protein are associated with elevated levels of ammonia, ornithine, and citrulline in affected individuals (Camacho et al. 1999). The second transporter, SLC25A2, identified later, is also expressed in normal cells and their apparently partly redundant function may explain the relatively mild symptoms associated with SLC25A15 deficiency compared to other defects of the urea cycle (Fiermonte et al. 2003).

Literature References

PubMed ID	Title	Journal	Year
12807890	The mitochondrial ornithine transporter. Bacterial expression, reconstitution, functional characterization, and tissue distribution of two human isoforms Fiermonte, G, Dolce, V, David, L, Santorelli, FM, Dionisi-Vici, C, Palmieri, F, Walker, JE	J Biol Chem	2003
10369256	Hyperornithinaemia-hyperammonaemia-homocitrullinuria syndrome is caused by mutations in a gene encoding a mitochondrial ornithine transporter. Camacho, JA, Obie, C, Biery, B, Goodman, BK, Hu, CA, Almashanu, S, Steel, G, Casey, R, Lambert, M, Mitchell, GA, Valle, D	Nat Genet	1999
12948741	Cloning and characterization of human ORNT2: a second mitochondrial ornithine transporter that can rescue a defective ORNT1 in patients with the hyperornithinemia-hyperammonemia-homocitrullinuria syndrome, a urea cycle disorder Camacho, JA, Rioseco-Camacho, N, Andrade, D, Porter, J, Kong, J	Mol Genet Metab	2003