homocysteine

Three steps

• (R)-lactic acidReach from here →
  1. Formation of Homocystine
  2. (R)-S-Lactoylglutathione methylglyoxal-lyase (isomerizing)
  3. (R)-S-Lactoylglutathione hydrolase

  Catalysed by GLO1, GLOD4, HAGH, HAGHLcytosolOne of 2 routes

• (S)-lactic acidReach from here →
  1. Formation of Homocystine
  2. transport of GSH and prostaglandin A2 (cytosol to extracellular)
  3. Transport of Prostaglandin A2, Lactate Antiport

  Catalysed by SLCO2A1cytosol, extracellular spaceOne of 4 routes

• 25-hydroxycholesterolReach 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. cholesterol + AH2 + O2 = 25-hydroxycholesterol + A + H2O

  Catalysed by MTR, CDKAL1, CH25Hcytosol

• N-methylserotoninReach from here →
  1. Formation of Homocystine
  2. transport of GSH and serotonin (cytosol to extracellular)
  3. S-Adenosyl-L-methionine:amine N-methyltransferase

  Catalysed by SLCO1A2, SLCO1B3, INMTcytosol, extracellular space

• 1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-oneReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. glyoxylate + L-methionine = 4-methylsulfanyl-2-oxobutanoate + glycine
  3. 1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one + O2 = 4-methylsulfanyl-2-oxobutanoate + formate + 2 H(+)

  Catalysed by MTR, AADAT, ADI1cytosol

• (5-hydroxyindol-3-yl)acetaldehydeReach from here →
  1. Formation of Homocystine
  2. transport of GSH and serotonin (cytosol to extracellular)
  3. 5-Hydroxytryptamine:oxygen oxidoreductase(deaminating)(flavin-containing)

  Catalysed by SLCO1A2, SLCO1B3, MAOA, MAOBcytosol, extracellular spaceOne of 2 routes

• S(8)-aminomethyldihydrolipoamideReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. dihydrolipoyl dehydrogenase ([protein]-N6-(lipoyl)lysine)

  Catalysed by MTR, SLC7A5, GLDC, GCSHcytosol, extracellular space, mitochondrial matrix

• taurineReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. bile acid-CoA:amino acid N-acyltransferase (taurodeoxycholate)

  Catalysed by CBS, NAGS, BAATcytosol, mitochondrial matrixOne of 4 routes

• all-trans-13,14-dihydroretinolReach 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. all-trans-13,14-dihydroretinol + A = all-trans-retinol + AH2

  Catalysed by MTR, CDKAL1, RETSATcytosol

• 2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-glycerolReach from here →
  1. Formation of Homocystine
  2. transport of arachidonate and GSH (cytosol to extracellular)
  3. fatty acid amide hydrolase (2-arachidonoylglycerol)

  Catalysed by FAAHcytosol, extracellular space

• malonaldehydeReach from here →
  1. Formation of Homocystine
  2. transport of GSH and prostaglandin H2 (cytosol to extracellular)
  3. thromboxane A synthase (12(S)-HHT)

  Catalysed by SLCO2A1, TBXAS1cytosol, extracellular spaceOne of 2 routes

• 3,3',5'-triiodo-L-thyronineReach 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. 3,3',5'-triiodo-L-thyronine + iodide + A + H(+) = L-thyroxine + AH2

  Catalysed by MTR, CDKAL1, DIO1, DIO3cytosolOne of 2 routes

• (R)-methylmalonyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. aldehyde dehydrogenase (2-methyl-3-oxopropanoate)

  Catalysed by CBS, NAGS, ALDH6A1cytosol, mitochondrial matrixOne of 2 routes

• (S)-methylmalonyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. (S)-methylmalonyl-CoA hydrolase

  Catalysed by CBS, NAGScytosol, mitochondrial matrix

• 3'-dephospho-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. acid phosphatase 2, lysosomal (CoA)

  Catalysed by CBS, NAGS, ACP2cytosol, mitochondrial matrix, lysosomeOne of 2 routes

• (2E)-dodecenoyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. (2E)-dodecenoyl-CoA formation

  Catalysed by CBS, NAGScytosol, mitochondrial matrixOne of 3 routes

• 4,8,12-trimethyltridecanoyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. propanoyl-CoA C-acyltransferase (3-ketopristanoyl-CoA)

  Catalysed by CBS, NAGS, ACAA1, MYO5Bcytosol, mitochondrial matrix, peroxisomeOne of 2 routes

• (6Z,9Z,12Z)-octadecatrienoyl-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 (gamma-linolenate)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 morecytosol, mitochondrial matrixOne of 7 routes

• (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoAReach from here →
  1. Formation of Homocystine
  2. transport of arachidonate and GSH (cytosol to extracellular)
  3. (5Z,8Z,11Z,14Z)-eicosatetraenoate + ATP + CoA = (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + AMP + diphosphate

  Catalysed by SLC27A2, ACSL4, ACSL3, ACSL1 and 7 morecytosol, extracellular space

• butanoyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Butanoate:CoA ligase (AMP-forming)

  Catalysed by CBS, NAGS, ACSM4, ACSM1 and 4 morecytosol, mitochondrial matrixOne of 9 routes

• choloyl-CoAReach from here →
  1. Formation of Homocystine
  2. solute carrier organic anion transporter (cholate)
  3. cholate + ATP + CoA = choloyl-CoA + AMP + diphosphate

  Catalysed by SLCO1A2, SLCO1B3, SLC27A5cytosol, extracellular space

• dodecanoyl-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 (lauric acid)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 morecytosol, mitochondrial matrixOne of 9 routes

• glutaryl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Production of Glutaryl Carnitine

  Catalysed by CBS, NAGS, CPT1A, CPT1C and 1 morecytosol, mitochondrial matrixOne of 2 routes

• eicosanoyl-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 (eicosanoate)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 morecytosol, mitochondrial matrixOne of 12 routes

• itaconyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Itaconate:CoA ligase (GDP-forming)

  Catalysed by CBS, NAGS, SUCLG1, SUCLG2 and 1 morecytosol, mitochondrial matrixOne of 2 routes

• (9Z,12Z)-octadecadienoyl-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 ((6Z,9Z)-octadecadienoic acid)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 morecytosol, mitochondrial matrixOne of 13 routes

• tetradecanoyl-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 (myristic acid)

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

• octanoyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Octanoyl-CoA:L-carnitine O-octanoyltransferase

  Catalysed by CBS, NAGS, CROTcytosol, mitochondrial matrixOne of 20 routes

• phytanoyl-CoAReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. phytanate-CoA ligase

  Catalysed by CBS, NAGScytosol, mitochondrial matrixOne of 5 routes

• octadecanoyl-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 (stearate)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 5 morecytosol, mitochondrial matrixOne of 15 routes

• 15-oxoprostaglandin E2Reach from here →
  1. Formation of Homocystine
  2. transport of GSH and prostaglandin E2 (cytosol to extracellular)
  3. prostaglandin E2 + NAD(+) = 15-oxoprostaglandin E2 + NADH + H(+)

  Catalysed by SLCO1A2, SLCO1B3, HPGDcytosol, extracellular spaceOne of 2 routes

• 15-oxoprostaglandin E1Reach from here →
  1. Formation of Homocystine
  2. transport of GSH and prostaglandin E1 (cytosol to extracellular)
  3. (13E)-(15S)-11alpha,15-dihydroxy-9-oxoprost-13-enoate:NADP+ 15-oxidoreductase

  Catalysed by SLCO2A1, CBR3, CBR1, DHRS4cytosol, extracellular spaceOne of 3 routes

• 15-oxoprostaglandin D2Reach from here →
  1. Formation of Homocystine
  2. transport of GSH and prostaglandin D2 (cytosol to extracellular)
  3. 15-dehydro-prostaglandin D2 reduction

  Catalysed by SLCO2A1cytosol, extracellular spaceOne of 2 routes

• 15-oxo-(5Z,8Z,11Z,13E)-eicosatetraenoateReach from here →
  1. Formation of Homocystine
  2. Glutathione: 15-HPETE oxidoreductase
  3. (15S)-15-Hydroxy-5,8,11-cis-13-trans-icosatetraenoate:NADP+ 15-oxidoreductase

  Catalysed by GPX5, GPX1, GPX2, GPX3 and 5 morecytosolOne of 3 routes

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

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

• sarcosineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. sarcosine + O2 + H2O = formaldehyde + glycine + H2O2

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

• (12S)-hydroperoxy-(5Z,8Z,10E,14Z)-eicosatetraenoateReach from here →
  1. Formation of Homocystine
  2. transport of arachidonate and GSH (cytosol to extracellular)
  3. (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 = (12S)-hydroperoxy-(5Z,8Z,10E,14Z)-eicosatetraenoate

  Catalysed by ALOX5, ALOX15, ALOX12cytosol, extracellular space

• thromboxane A2Reach from here →
  1. Formation of Homocystine
  2. transport of GSH and thromboxane B2 (cytosol to extracellular)
  3. thromboxane A2 hydrolysis

  Catalysed by SLCO1B1cytosol, extracellular space, endoplasmic reticulumOne of 4 routes

• (15S)-hydroperoxy-(5Z,8Z,11Z,13E)-eicosatetraenoateReach from here →
  1. Formation of Homocystine
  2. transport of arachidonate and GSH (cytosol to extracellular)
  3. (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 = (15S)-hydroperoxy-(5Z,8Z,11Z,13E)-eicosatetraenoate

  Catalysed by ALOX15B, ALOX15, ALOX12cytosol, extracellular space

• (5S)-hydroperoxy-(6E,8Z,11Z,14Z)-eicosatetraenoateReach from here →
  1. Formation of Homocystine
  2. transport of arachidonate and GSH (cytosol to extracellular)
  3. (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 = (5S)-hydroperoxy-(6E,8Z,11Z,14Z)-eicosatetraenoate

  Catalysed by ALOX5cytosol, extracellular space

• (6S)-5,6,7,8-tetrahydrofolateReach from here →
  1. L-serine hydro-lyase (adding homocysteine
  2. L-homocysteine + L-serine = L,L-cystathionine + H2O
  3. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine

  Catalysed by CBS, MTRcytosolOne of 4 routes

• (6R)-5,10-methenyltetrahydrofolateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. 5,10-Methylenetetrahydrofolate:glycine hydroxymethyltransferase
  3. 5,10-methylenetetrahydrofolate:NAD+ oxidoreductase

  Catalysed by MTR, SHMT1, MTHFD2, MTHFD2Lcytosol, mitochondrial matrixOne of 8 routes

• 2-(N(omega)-L-arginino)succinateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of arginine and methionine (cytosol to extracellular)
  3. 2-(Nomega-L-arginino)succinate arginine-lyase (fumarate-forming)

  Catalysed by MTR, SLC7A6, ASLcytosol, extracellular spaceOne of 6 routes

• 4-guanidinobutanoateReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of arginine and methionine (cytosol to extracellular)
  3. 4-aminobutanoate + L-arginine = 4-guanidinobutanoate + L-ornithine

  Catalysed by MTR, SLC7A6, GATMcytosol, extracellular space

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

  Catalysed by MTR, SLC7A5, SLC7A8cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 3 routes

• N(6)-(1,2-dicarboxyethyl)-AMPReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. L-aspartate(in) + L-methionine(out) = L-aspartate(out) + L-methionine(in)
  3. IMP:L-aspartate ligase (GDP-forming)

  Catalysed by MTR, SLC7A13, ADSS2, ADSS1cytosol, inner side of the membrane, outer side of the membraneOne of 2 routes

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

  Catalysed by MTR, SLC7A6, GATMcytosol, extracellular space

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

  Catalysed by MTR, SLC7A5, SLC7A8cytosol, extracellular space, inner side of the membrane, outer side of the membraneOne of 8 routes

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

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

• an N-acylglycineReach from here →
  1. 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
  2. transport of glycine and methionine (cytosol to extracellular)
  3. an acyl-CoA + glycine = an N-acylglycine + CoA + H(+)

  Catalysed by MTR, SLC7A5, GLYATL3, GLYAT and 1 morecytosol, extracellular space