L-cystine

1. L-cystine(out) + L-aspartate(in) = L-cystine(in) + L-aspartate(out)
2. IMP:L-aspartate ligase (GDP-forming)

Catalysed by SLC7A13, ADSS2, ADSS1inner side of the membrane, outer side of the membrane, cytosolOne of 2 routes

1. L-cystine(out) + L-arginine(in) = L-cystine(in) + L-arginine(out)
2. beta-alanine + L-arginine = 3-guanidinopropanoate + L-ornithine

Catalysed by SLC7A9, GATMinner side of the membrane, outer side of the membrane

1. L-cystine(out) + L-arginine(in) = L-cystine(in) + L-arginine(out)
2. L-histidine(out) + L-arginine(in) + Na(+)(out) = L-histidine(in) + L-arginine(out) + Na(+)(in)

Catalysed by SLC7A9, SLC7A6inner side of the membrane, outer side of the membraneOne of 3 routes

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. L-Cysteine:2-oxoglutarate aminotransferase

Catalysed by TXNRD1, TXNRD3, TXNRD2, GOT2 and 1 morecytosolOne of 4 routes

1. L-cystine thiocysteine-lyase (deaminating
2. (R)-3-amino-2-methylpropanoate + pyruvate = 2-methyl-3-oxopropanoate + L-alanine

Catalysed by CTH, AGXT2cytosol

1. L-cystine(out) + L-arginine(in) = L-cystine(in) + L-arginine(out)
2. L-Arginine:glycine amidinotransferase

Catalysed by SLC7A9, GATMinner side of the membrane, outer side of the membrane, cytosolOne of 2 routes

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. D-threonine(out) + L-alanine(in) = D-threonine(in) + L-alanine(out)

Catalysed by SLC7A9, SLC3A1, SLC7A10extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 2 routes

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. transport of cysteine and methionine (cytosol to extracellular)

Catalysed by TXNRD1, TXNRD3, TXNRD2, SLC7A5cytosol, extracellular spaceOne of 27 routes

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. transport of cysteine and tryptophan (cytosol to extracellular)

Catalysed by TXNRD1, TXNRD3, TXNRD2, SLC7A5cytosol, extracellular spaceOne of 16 routes

1. cystine to cysteine conversion
2. 2 glutathione + NADP(+) = glutathione disulfide + NADPH + H(+)

Catalysed by GSRcytosolOne of 4 routes

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. L-threonine(out) + L-alanine(in) = L-threonine(in) + L-alanine(out)

Catalysed by SLC7A9, SLC3A1, SLC7A10extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 4 routes

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. L-kynurenine + H2O = anthranilate + L-alanine + H(+)

Catalysed by SLC7A9, SLC3A1, KYNUextracellular space, cytosolOne of 3 routes

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. beta-alanine(out) + L-alanine(in) = beta-alanine(in) + L-alanine(out)

Catalysed by SLC7A9, SLC3A1, SLC7A10extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 4 routes

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. transport of asparagine and cysteine (cytosol to extracellular)

Catalysed by TXNRD1, TXNRD3, TXNRD2, SLC7A5cytosol, extracellular spaceOne of 17 routes

1. L-cystine(out) + L-arginine(in) = L-cystine(in) + L-arginine(out)
2. taurine + L-arginine = taurocyamine + L-ornithine

Catalysed by SLC7A9, GATMinner side of the membrane, outer side of the membrane

1. L-cystine(out) + L-aspartate(in) = L-cystine(in) + L-aspartate(out)
2. N(4)-(beta-N-acetyl-D-glucosaminyl)-L-asparagine + H2O = N-acetyl-beta-D-glucosaminylamine + L-aspartate + H(+)

Catalysed by SLC7A13, AGAinner side of the membrane, outer side of the membrane

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. transport of cysteine and phenylalanine (cytosol to extracellular)

Catalysed by TXNRD1, TXNRD3, TXNRD2, SLC7A5cytosol, extracellular spaceOne of 24 routes

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. 3-hydroxy-L-kynurenine + H2O = 3-hydroxyanthranilate + L-alanine + H(+)

Catalysed by SLC7A9, SLC3A1, KYNUextracellular space, cytosol

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. L-glutamate:L-cysteine gamma-ligase (ADP-forming)

Catalysed by TXNRD1, TXNRD3, TXNRD2, GCLC and 1 morecytosolOne of 2 routes

1. L-cystine(out) + L-aspartate(in) = L-cystine(in) + L-aspartate(out)
2. L-tyrosine(out) + L-aspartate(in) = L-tyrosine(in) + L-aspartate(out)

Catalysed by SLC7A13inner side of the membrane, outer side of the membraneOne of 2 routes

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. N(omega),N(omega)-dimethyl-L-arginine + pyruvate = 5-(3,3-dimethylguanidino)-2-oxopentanoate + L-alanine

Catalysed by SLC7A9, SLC3A1, AGXT2extracellular space, cytosolOne of 4 routes

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. trans-4-hydroxy-L-proline(out) + L-alanine(in) + Na(+)(out) = trans-4-hydroxy-L-proline(in) + L-alanine(out) + Na(+)(in)

Catalysed by SLC7A9, SLC3A1, SLC1A4extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 2 routes

1. L-cystine(out) + L-aspartate(in) = L-cystine(in) + L-aspartate(out)
2. 1-(5-Phosphoribosyl)-5-amino-4-carboxyimidazole:L-aspartate ligase (ADP-forming)

Catalysed by SLC7A13, PAICSinner side of the membrane, outer side of the membrane, cytosolOne of 2 routes

1. L-cystine(out) + L-arginine(in) = L-cystine(in) + L-arginine(out)
2. L-arginine + O2 + H2O = 5-guanidino-2-oxopentanoate + H2O2 + NH4(+)

Catalysed by SLC7A9, IL4I1inner side of the membrane, outer side of the membrane

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. 2 L-cysteine = S-sulfanyl-L-cysteine + L-alanine

Catalysed by TXNRD1, TXNRD3, TXNRD2, CARS2cytosol

1. L-cystine thiocysteine-lyase (deaminating
2. (3S)-citramalyl-CoA = pyruvate + acetyl-CoA

Catalysed by CTH, CLYBLcytosol

1. L-cystine thiocysteine-lyase (deaminating
2. L-ornithine + pyruvate = 5-amino-2-oxopentanoate + L-alanine

Catalysed by CTH, AGXT2cytosol

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. (R)-4'-phosphopantothenate:L-cysteine ligase

Catalysed by TXNRD1, TXNRD3, TXNRD2, PPCScytosolOne of 4 routes

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. L-proline(out) + L-alanine(in) + Na(+)(out) = L-proline(in) + L-alanine(out) + Na(+)(in)

Catalysed by SLC7A9, SLC3A1, SLC1A4extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 2 routes

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. L-Cysteine:oxygen oxidoreductase

Catalysed by TXNRD1, TXNRD3, TXNRD2, CDO1cytosolOne of 6 routes

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. gamma-glutamyltransferase (alanine)

Catalysed by SLC7A9, SLC3A1, GGTLC3, GGT1 and 4 moreextracellular space, cytosolOne of 2 routes

1. L-cystine thiocysteine-lyase (deaminating
2. (4R)-4-hydroxy-2-oxoglutarate = glyoxylate + pyruvate

Catalysed by CTH, HOGA1cytosol

1. L-cystine(out) + L-arginine(in) = L-cystine(in) + L-arginine(out)
2. L-arginine,NADPH:oxygen oxidoreductase (N-(omega)-hydroxyarginine-forming)

Catalysed by SLC7A9, NOS3, NOS1, NOS2inner side of the membrane, outer side of the membrane, cytosol

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. Mo-molybdopterin + L-cysteine + AH2 = thio-Mo-molybdopterin + L-alanine + A + H2O

Catalysed by SLC7A9, SLC3A1, MOCOSextracellular space, cytosol

1. L-cystine thiocysteine-lyase (deaminating
2. (4S)-4-hydroxy-2-oxoglutarate = glyoxylate + pyruvate

Catalysed by CTH, HOGA1cytosol

1. Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter
2. 2-oxobutanoate + L-alanine = (2S)-2-aminobutanoate + pyruvate

Catalysed by SLC7A9, SLC3A1, AGXT2extracellular space, cytosol

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. Mo-molybdopterin + L-cysteine + AH2 = thio-Mo-molybdopterin + L-alanine + A + H2O

Catalysed by TXNRD1, TXNRD3, TXNRD2, MOCOScytosol

1. L-cystine thiocysteine-lyase (deaminating
2. pyruvate:thiamin diphosphate acetaldehydetransferase (decarboxylating)

Catalysed by CTH, PDHA1, PDHB, PDHA2cytosol, mitochondrial matrix

1. thioredoxin-disulfide reductase (NADPH) (cystine)
2. transport of cysteine and tryptophan (cytosol to extracellular)
3. beta-carboline hydrolysis

Catalysed by TXNRD1, TXNRD3, TXNRD2, SLC7A5cytosol, extracellular space

1. L-cystine thiocysteine-lyase (deaminating
2. transport of acetoacetate and pyruvate (cytosol to mitochondria)
3. (S)-3-hydroxybutanoate + 2-oxoglutarate = (R)-2-hydroxyglutarate + acetoacetate