homocysteine

Three steps

• CHEBI:27540Reach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. medium-chain acyl-CoA ligase (hexanoic acid)

  Catalysed by CBS, NAGS, ACSM4, ACSM1 and 4 morecytosol, mitochondrial matrixOne of 6 routes

• selenomethionineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. Selenomethionine methanethiol-lyase (deaminating)

  Catalysed by CBS, CTHcytosolOne of 3 routes

• CHEBI:27760Reach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. Selenocystathionine Lysteine-lyase (deaminating)

  Catalysed by CBS, CTHcytosol

• 3,4-dihydroxyphenylacetaldehydeReach from here →
  1. Formation of Homocystine
  2. transport of dopamine and GSH (cytosol to extracellular)
  3. monoamine oxidase (dopamine)

  Catalysed by SLCO1A2, SLCO1B3, AOC2, AOC1 and 3 morecytosol, extracellular spaceOne of 2 routes

• elaidic acidReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. long-chain-fatty-acid-CoA ligase (elaidate)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 morecytosol, mitochondrial matrixOne of 5 routes

• 5-hydroxytryptophanReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of methionine and tryptophan (cytosol to extracellular)
  3. L-Tryptophan, Tetrahydrobiopterin:Oxygen Oxidoreductase (5-Hydroxylating)

  Catalysed by MTR, SLC7A5, TPH1, TPH2cytosol, extracellular spaceOne of 2 routes

• CHEBI:28701Reach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Propanoyl-CoA:acetyl-CoA C-acyltransferase

  Catalysed by CBS, NAGS, ACAA1, SCP2 and 1 morecytosol, mitochondrial matrix, peroxisomeOne of 7 routes

• pyridoxine 5'-phosphateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of alanine and methionine (cytosol to extracellular)
  3. L-selenocysteine selenide-lyase (L-alanine-forming)

  Catalysed by MTR, SLC7A5, SCLYcytosol, extracellular space

• CHEBI:28918Reach from here →
  1. Formation of Homocystine
  2. transport of GSH and noradrenaline (cytosol to extracellular)
  3. S-Adenosyl-L-methionine:phenylethanolamine N-methyltransferase

  Catalysed by SLCO1A2, SLCO1B3, PNMTcytosol, extracellular space

• N-acetyl-L-cysteineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. N-acetylglutamate synthase (N-acetyl-L-cysteine)

  Catalysed by CBS, CTH, NAGScytosol, mitochondrial matrix

• a dicarboxylateReach from here →
  1. Formation of Homocystine
  2. transport of GSH and prostaglandin E2 (cytosol to extracellular)
  3. prostaglandin E2(out) + a dicarboxylate(in) = prostaglandin E2(in) + a dicarboxylate(out)

  Catalysed by SLCO1A2, SLCO1B3, SLC22A6cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 4 routes

• iron(2+)Reach from here →
  1. Formation of Homocystine
  2. glutathione:dehydroascorbate oxidoreductase
  3. cytochrome b reductase (ascorbate)

  Catalysed by CYBRD1cytosol, extracellular space

• K(+)Reach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. K(+)(in) + L-cysteine(out) + 3 Na(+)(out) + H(+)(out) = K(+)(out) + L-cysteine(in) + 3 Na(+)(in) + H(+)(in)

  Catalysed by CBS, CTH, SLC1A1cytosol, inner side of the membrane, outer side of the membraneOne of 5 routes

• Cys-tRNA(Cys)Reach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. L-Cysteine:tRNA(Cys) ligase (AMP-forming)

  Catalysed by CBS, CTH, CARS1cytosol

• Phe-tRNA(Phe)Reach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of methionine and phenylalanine (cytosol to extracellular)
  3. L-Phenylalanine:tRNA(Ala) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, FARSB, FARSAcytosol, extracellular space

• Gly-tRNA(Gly)Reach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. glycine:tRNA(Gly) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, GARS1cytosol, extracellular space

• Asp-tRNA(Asp)Reach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. L-aspartate(in) + L-methionine(out) = L-aspartate(out) + L-methionine(in)
  3. L-Aspartate:tRNA(Asp) ligase (AMP-forming)

  Catalysed by MTR, SLC7A13, DARS1cytosol, inner side of the membrane, outer side of the membrane

• Trp-tRNA(Trp)Reach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of methionine and tryptophan (cytosol to extracellular)
  3. L-Tryptophan -tRNA(Trp) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, WARS1cytosol, extracellular space

• Ile-tRNA(Ile)Reach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of isoleucine and methionine (cytosol to extracellular)
  3. L-Isoleucine:tRNA(Ile) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, IARS1cytosol, extracellular space

• Gln-tRNA(Gln)Reach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glutamine and methionine (cytosol to extracellular)
  3. L-Glutamine:tRNA(Gln) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, QARS1cytosol, extracellular space

• isocyanateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of citrulline and methionine (cytosol to extracellular)
  3. L-citrulline + H(+) = isocyanate + L-ornithine

  Catalysed by MTR, SLC7A6, LACC1cytosol, extracellular space

• Asn-tRNA(Asn)Reach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of asparagine and methionine (cytosol to extracellular)
  3. L-Asparagine:tRNA(Asn) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, NARS1cytosol, extracellular space

• hydrogenselenideReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. N(6)-L-threonylcarbamoyladenosine(37) in tRNA + (sulfur carrier)-SH + AH2 + 2 S-adenosyl-L-methionine = 2-methylsulfanyl-N(6)-L-threonylcarbamoyladenosine(37) in tRNA + (sulfur carrier)-H + 5'-deoxyadenosine + L-methionine + A + S-adenosyl-L-homocysteine + 2 H(+)
  3. L-selenocysteine + AH2 = hydrogenselenide + L-alanine + A + H(+)

  Catalysed by MTR, CDKAL1, SCLYcytosol

• hydrogen sulfideReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. L-cysteine hydrogen-sulfide-lyase (deaminating

  Catalysed by CBS, CTHcytosolOne of 3 routes

• acetateReach from here →
  1. Formation of Homocystine
  2. transport of acetylcholine and GSH (cytosol to extracellular)
  3. Acetylcholine aectylhydrolase

  Catalysed by SLCO1A2, SLCO1B3, BCHE, ACHEcytosol, extracellular spaceOne of 3 routes

• CHEBI:30249Reach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of methionine and tryptophan (cytosol to extracellular)
  3. L-tryptophan:oxygen 2,3-oxidoreductase (decyclizing)

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

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

  Catalysed by MTR, SLC6A14, SLC26A4cytosol, extracellular spaceOne of 3 routes

• malonic acidReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of chloride and methionine (cytosol to extracellular)
  3. Malonate Transport, Antiport with Chloride

  Catalysed by MTR, SLC6A14cytosol, extracellular spaceOne of 2 routes

• glutarateReach from here →
  1. Formation of Homocystine
  2. solute carrier organic anion transporter (glycocholate)
  3. glycocholate(out) + glutarate(in) = glycocholate(in) + glutarate(out)

  Catalysed by SLCO1A2, SLCO1B3, SLC22A24cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 8 routes

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

  Catalysed by MTR, SLC3A2, SLC7A5, SLC7A7cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 5 routes

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

  Catalysed by MTR, SLC7A6, SLC25A2cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 2 routes

• putrescineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of arginine and methionine (cytosol to extracellular)
  3. Putrescine Export via Putrescine/Arginine Antiporter

  Catalysed by MTR, SLC7A6, SLC3A2, SLC7A7cytosol, extracellular spaceOne of 4 routes

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

  Catalysed by MTR, SLC7A6, SLC25A2cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 2 routes

• N-carbamoyl-L-aspartateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. L-aspartate(in) + L-methionine(out) = L-aspartate(out) + L-methionine(in)
  3. carbamoyl phosphate + L-aspartate = N-carbamoyl-L-aspartate + phosphate + H(+)

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

• methylarsonateReach from here →
  1. Formation of Homocystine
  2. Glutathione: 5-HPETE oxidoreductase
  3. methylarsonate + 2 glutathione + H(+) = methylarsonous acid + glutathione disulfide + H2O

  Catalysed by GPX5, GPX1, GPX2, GPX3 and 7 morecytosol

• thiosulfateReach from here →
  1. Formation of Homocystine
  2. Glutathione: 5-HPETE oxidoreductase
  3. thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)

  Catalysed by GPX5, GPX1, GPX2, GPX3 and 6 morecytosolOne of 2 routes

• di-mu-sulfido-diiron(2+)Reach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. De novo synthesis of 2Fe2S

  Catalysed by CBS, CTH, NDUFAB1, FDXR and 5 morecytosol, mitochondrial matrix

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

  Catalysed by MTR, SLC7A5, BCAT2, BCAT1cytosol, extracellular space

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

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

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

  Catalysed by MTR, SLC7A5, SLC7A10cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 10 routes

• fatty acidReach from here →
  1. Formation of Homocystine
  2. transport of arachidonate and GSH (cytosol to extracellular)
  3. (10Z)-heptadecenoic acid formation

  No catalyst recordedcytosol, extracellular spaceOne of 4 routes

• L-alpha-aminobutyric acidReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. glutamic-pyruvic transaminase ((S)-2-aminobutanoate)

  Catalysed by CBS, CTH, GPTcytosol

• 5-aminolevulinateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. succinyl-CoA + glycine + H(+) = 5-aminolevulinate + CO2 + CoA

  Catalysed by MTR, SLC7A5, ALAS1, ALAS2cytosol, extracellular space

• 3-methyl-2-oxovaleric acidReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of isoleucine and methionine (cytosol to extracellular)
  3. L-Leucine:2-oxoglutarate aminotransferase

  Catalysed by MTR, SLC7A5, BCAT1cytosol, extracellular spaceOne of 2 routes

• 3-(4-hydroxyphenyl)pyruvateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of methionine and tyrosine (cytosol to extracellular)
  3. L-tyrosine:2-oxoglutarate aminotransferase

  Catalysed by MTR, SLC7A5, GOT2, GOT1 and 1 morecytosol, extracellular spaceOne of 3 routes

• glycochenodeoxycholateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. chenodeoxycholoyl-CoA + glycine = glycochenodeoxycholate + CoA + H(+)

  Catalysed by MTR, SLC7A5, BAATcytosol, extracellular space

• glycochenodeoxycholic acidReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. bile acid-CoA: amino acid N-acyltransferase

  Catalysed by MTR, SLC7A5, BAATcytosol, extracellular space, peroxisomeOne of 3 routes

• glyoxylateReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-cystathionine cysteine-lyase (deaminating
  3. (2S)-2-aminobutanoate + glyoxylate = 2-oxobutanoate + glycine

  Catalysed by CBS, CTH, AGXT2cytosolOne of 13 routes

• CHEBI:37946Reach from here →
  1. Formation of Homocystine
  2. transport of dopamine and GSH (cytosol to extracellular)
  3. aryl sulfotransferase (dopamine)

  Catalysed by SLCO1A2, SLCO1B3, SULT1A3, SULT1A4 and 2 morecytosol, extracellular space

• L-2-amino-3-oxobutanoic acidReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. Acetyl-CoA:glycine C-acetyltransferase

  Catalysed by MTR, SLC7A5, GCATcytosol, extracellular space, mitochondrial matrix