homocysteine

Three steps

• 2-oxo-3-sulfanylpropanoateReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. L-Cysteine:2-oxoglutarate aminotransferase

  Catalysed by CBS, CTH, GOT2, GOT1cytosolOne of 3 routes

• guanidinoacetateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. L-Arginine:glycine amidinotransferase

  Catalysed by MTR, SLC7A5, GATMcytosol, extracellular spaceOne of 5 routes

• sphing-4-enineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. acyl-CoA:sphingosine N-acyltransferase

  Catalysed by CBS, NAGS, ASAH1, ACER2 and 2 morecytosol, mitochondrial matrix, Golgi apparatusOne of 2 routes

• D-threonineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of alanine and methionine (cytosol to extracellular)
  3. D-threonine(out) + L-alanine(in) = D-threonine(in) + L-alanine(out)

  Catalysed by MTR, SLC7A5, SLC7A10cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 2 routes

• spermidineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. diamine N-acetyltransferase (N1-acetylspermidine)

  Catalysed by CBS, NAGS, SAT1, SAT2cytosol, mitochondrial matrixOne of 3 routes

• L-dopaquinoneReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of methionine and tyrosine (cytosol to extracellular)
  3. L-Tyrosine,L-dopa:oxygen oxidoreductase

  Catalysed by MTR, SLC7A5, TYRcytosol, extracellular space

• glutathioneReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. gamma-L-glutamyl-L-cysteine + glycine + ATP = glutathione + ADP + phosphate + H(+)

  Catalysed by MTR, SLC7A5, GSScytosol, extracellular spaceOne of 17 routes

• L-threonineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. L-threonine = 2-oxobutanoate + NH4(+)

  Catalysed by CBS, CTH, SDS, SDSLcytosolOne of 9 routes

• L-saccharopineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of lysine and methionine (cytosol to extracellular)
  3. N6-(L-1,3-Dicarboxypropyl)-L-lysine:NADP+ oxidoreductase (L-lysine-forming)

  Catalysed by MTR, SLC7A6, AASScytosol, extracellular space, mitochondrial matrix

• L-kynurenineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of alanine and methionine (cytosol to extracellular)
  3. L-kynurenine + H2O = anthranilate + L-alanine + H(+)

  Catalysed by MTR, SLC7A5, KYNUcytosol, extracellular spaceOne of 5 routes

• beta-alanineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of alanine and methionine (cytosol to extracellular)
  3. beta-alanine(out) + L-alanine(in) = beta-alanine(in) + L-alanine(out)

  Catalysed by MTR, SLC7A5, SLC7A10cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 6 routes

• taurocyamineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of arginine and methionine (cytosol to extracellular)
  3. taurine + L-arginine = taurocyamine + L-ornithine

  Catalysed by MTR, SLC7A6, GATMcytosol, extracellular space

• L-glutamate 5-semialdehydeReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of methionine and ornithine (cytosol to extracellular)
  3. L-ornithine + 2-oxoglutarate = L-glutamate 5-semialdehyde + L-glutamate

  Catalysed by MTR, SLC7A6, OATcytosol, extracellular space

• N(4)-(beta-N-acetyl-D-glucosaminyl)-L-asparagineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. L-aspartate(in) + L-methionine(out) = L-aspartate(out) + L-methionine(in)
  3. N(4)-(beta-N-acetyl-D-glucosaminyl)-L-asparagine + H2O = N-acetyl-beta-D-glucosaminylamine + L-aspartate + H(+)

  Catalysed by MTR, SLC7A13, AGAcytosol, inner side of the membrane, outer side of the membrane

• 3-hydroxy-L-kynurenineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of alanine and methionine (cytosol to extracellular)
  3. 3-hydroxy-L-kynurenine + H2O = 3-hydroxyanthranilate + L-alanine + H(+)

  Catalysed by MTR, SLC7A5, KYNUcytosol, extracellular space

• gamma-L-glutamyl-L-cysteineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. L-glutamate:L-cysteine gamma-ligase (ADP-forming)

  Catalysed by CBS, CTH, GCLC, GCLMcytosolOne of 2 routes

• 6-amino-2-oxohexanoateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of lysine and methionine (cytosol to extracellular)
  3. L-lysine:oxygen 2-oxidoreductase (deaminating)

  Catalysed by MTR, SLC7A6cytosol, extracellular space, peroxisome

• carbamoyl phosphateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glutamine and methionine (cytosol to extracellular)
  3. HCO3-:L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating)

  Catalysed by MTR, SLC7A5, CADcytosol, extracellular spaceOne of 4 routes

• N,N-dimethylglycineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-homocysteine + L-serine = L,L-cystathionine + H2O
  3. L-homocysteine + glycine betaine = N,N-dimethylglycine + L-methionine

  Catalysed by CBS, BHMTcytosol

• L-tyrosineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. L-tyrosine + glyoxylate = 3-(4-hydroxyphenyl)pyruvate + glycine

  Catalysed by MTR, SLC7A5, AADATcytosol, extracellular spaceOne of 4 routes

• N(omega),N(omega)-dimethyl-L-arginineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. N(omega),N(omega)-dimethyl-L-arginine + glyoxylate = 5-(3,3-dimethylguanidino)-2-oxopentanoate + glycine

  Catalysed by MTR, SLC7A5, AGXT2cytosol, extracellular spaceOne of 7 routes

• an acyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. acyl-CoA:sphingosine N-acyltransferase

  Catalysed by CBS, NAGS, ASAH1, ACER2 and 2 morecytosol, mitochondrial matrix, Golgi apparatusOne of 2 routes

• trans-4-hydroxy-L-prolineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of alanine and methionine (cytosol to extracellular)
  3. trans-4-hydroxy-L-proline(out) + L-alanine(in) + Na(+)(out) = trans-4-hydroxy-L-proline(in) + L-alanine(out) + Na(+)(in)

  Catalysed by MTR, SLC7A5, SLC1A4cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 2 routes

• (2S)-2-[5-amino-1-(5-phospho-beta-D-ribosyl)imidazole-4-carboxamido]succinateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. L-aspartate(in) + L-methionine(out) = L-aspartate(out) + L-methionine(in)
  3. 1-(5-Phosphoribosyl)-5-amino-4-carboxyimidazole:L-aspartate ligase (ADP-forming)

  Catalysed by MTR, SLC7A13, PAICScytosol, inner side of the membrane, outer side of the membraneOne of 4 routes

• kynurenateReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. 2-oxobutanoate + L-kynurenine = (2S)-2-aminobutanoate + kynurenate + H2O

  Catalysed by CBS, CTH, AADATcytosolOne of 2 routes

• 5-formamido-1-(5-phospho-D-ribosyl)imidazole-4-carboxamideReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. phosphoribosylaminoimidazolecarboxamide formyltransferase (10-formyl-THF)
  3. (6R)-10-formyltetrahydrofolate + 5-amino-1-(5-phospho-beta-D-ribosyl)imidazole-4-carboxamide = 5-formamido-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide + (6S)-5,6,7,8-tetrahydrofolate

  Catalysed by MTR, ATICcytosolOne of 2 routes

• 5-guanidino-2-oxopentanoateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of arginine and methionine (cytosol to extracellular)
  3. L-arginine + O2 + H2O = 5-guanidino-2-oxopentanoate + H2O2 + NH4(+)

  Catalysed by MTR, SLC7A6, IL4I1cytosol, extracellular space

• (3Z)-dodecenoyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. acetyl-CoA C-acyltransferase (3-oxomyrist-5-enoyl-CoA)

  Catalysed by CBS, NAGS, HADHA, ACAA2 and 1 morecytosol, mitochondrial matrixOne of 3 routes

• S-sulfanyl-L-cysteineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. 2 L-cysteine = S-sulfanyl-L-cysteine + L-alanine

  Catalysed by CBS, CTH, CARS2cytosol

• N(tau)-methylhistamineReach from here →
  1. Formation of Homocystine
  2. transport of GSH and histamine (cytosol to extracellular)
  3. S-Adenosyl-L-methionine:histamine N-tele-methyltransferase

  Catalysed by SLCO1A2, SLCO1B3, HNMTcytosol, extracellular spaceOne of 3 routes

• N-formyl-L-kynurenineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of methionine and tryptophan (cytosol to extracellular)
  3. L-tryptophan + O2 = N-formyl-L-kynurenine

  Catalysed by MTR, SLC7A5, IDO1, TDO2 and 1 morecytosol, extracellular space

• (25R)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-oyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. 3alpha,7alpha,12alpha-trihydroxy-5beta-cholestanoate:CoA ligase (AMP-forming)

  Catalysed by CBS, NAGS, SLC27A2, SLC27A5cytosol, mitochondrial matrix, endoplasmic reticulumOne of 3 routes

• 5-phospho-beta-D-ribosylamineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glutamine and methionine (cytosol to extracellular)
  3. phosphoribosyl pyrophosphate amidotransferase (glutamine)

  Catalysed by MTR, SLC7A5, PPATcytosol, extracellular spaceOne of 2 routes

• D-glucosamine 6-phosphateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glutamine and methionine (cytosol to extracellular)
  3. D-fructose 6-phosphate + L-glutamine = D-glucosamine 6-phosphate + L-glutamate

  Catalysed by MTR, SLC7A5, GFPT2, GFPT1cytosol, extracellular space

• 5-amino-2-oxopentanoateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of methionine and ornithine (cytosol to extracellular)
  3. L-ornithine + pyruvate = 5-amino-2-oxopentanoate + L-alanine

  Catalysed by MTR, SLC7A6, AGXT2cytosol, extracellular spaceOne of 2 routes

• deoxycholoyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. cholate-CoA ligase (3alpha,12alpha-dihydroxy-5beta-cholanate)

  Catalysed by CBS, NAGS, SLC27A2, SLC27A5cytosol, mitochondrial matrixOne of 4 routes

• hyodeoxycholateReach from here →
  1. Formation of Homocystine
  2. transport of GSH and lithocholate (cytosol to extracellular)
  3. cytochrome P450 (lithocholate)

  Catalysed by SLCO1A2, SLCO1B3, CYP3A4cytosol, extracellular space

• N-formimidoyl-L-glutamateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. 5-Formiminotetrahydrofolate:L-glutamate N-formiminotransferase
  3. 5-Formiminotetrahydrofolate:L-glutamate N-formiminotransferase

  Catalysed by MTR, FTCDcytosol

• N-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-glycineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + glycine = N-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-glycine + CoA + H(+)

  Catalysed by MTR, SLC7A5, GLYATL2cytosol, extracellular spaceOne of 3 routes

• N-[(R)-4-phosphopantothenoyl]-L-cysteineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. (R)-4'-phosphopantothenate:L-cysteine ligase

  Catalysed by CBS, CTH, PPCScytosolOne of 4 routes

• monodehydro-L-ascorbate radicalReach from here →
  1. Formation of Homocystine
  2. transport of dopamine and GSH (cytosol to extracellular)
  3. dopamine + 2 L-ascorbate + O2 = (R)-noradrenaline + 2 monodehydro-L-ascorbate radical + H2O

  Catalysed by SLCO1A2, SLCO1B3, DBHcytosol, extracellular spaceOne of 9 routes

• 4-aminobutanoateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of chloride and methionine (cytosol to extracellular)
  3. transport of 4-aminobutyrate and chloride (cytosol to extracellular)

  Catalysed by MTR, SLC6A14, SLC6A12cytosol, extracellular spaceOne of 4 routes

• 3-iodo-L-tyrosineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of methionine and tyrosine (cytosol to extracellular)
  3. thyroid peroxidase (iodine)

  Catalysed by MTR, SLC7A5, TPOcytosol, extracellular spaceOne of 2 routes

• L-prolineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of alanine and methionine (cytosol to extracellular)
  3. L-proline(out) + L-alanine(in) + Na(+)(out) = L-proline(in) + L-alanine(out) + Na(+)(in)

  Catalysed by MTR, SLC7A5, SLC1A4cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 2 routes

• N-benzoylglycineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. Hippurate (Benzoylglycinate) Formation

  Catalysed by MTR, SLC7A5cytosol, extracellular space, mitochondrial matrixOne of 2 routes

• 3-sulfino-L-alanineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. L-Cysteine:oxygen oxidoreductase

  Catalysed by CBS, CTH, CDO1cytosolOne of 6 routes

• decanoyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. medium-chain acyl-CoA ligase (decanoic acid)

  Catalysed by CBS, NAGS, ACSM4, ACSM1 and 4 morecytosol, mitochondrial matrixOne of 7 routes

• (2E)-hexadecenoyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Carnitine O-Palmitoyltransferase

  Catalysed by CBS, NAGS, CPT1A, CPT1C and 1 morecytosol, mitochondrial matrixOne of 4 routes

• (9Z)-hexadecenoyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. long-chain-fatty-acid-CoA ligase (palmitolate)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 morecytosol, mitochondrial matrixOne of 11 routes

• 3-hydroxyisovaleryl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. (3-Hydroxyisovalerylcoa->3-Hydroxyisovalerylcarnitine)

  Catalysed by CBS, NAGS, CPT1A, CPT1Bcytosol, mitochondrial matrix