Thiamine metabolic pathways (WP4297)

Thiamine is absorbed in the form of thiamine or thiamine monophosphate and transported through the plasma membrane by thiamine transporter 1 (THTR1) and thiamine transporter 2 (THTR2), which are encoded for by the genes SLC19A2 and SLC19A3, respectively. Upon cell entrance, thiamine undergoes pyrophosphorylation by thiamine pyrophosphokinase (TPK) to thiamine pyrophosphate (TPP). TPP is the active form of thiamine and serves as a cofactor of transketolase in the pentose phosphate pathway in the cytosol. TPP also functions as a cofactor for pyruvate, ketoglutarate and branched chain alpha-keto acid dehydrogenases in the mitochondrion after entrance via TPP transporter encoded by SLC25A19. This pathway was inspired by Chapter 15 (Thiamine Disorders) of the book of Blau (ISBN 3642403360 (978-3642403361)).
last edited


Youssefwalid, Egonw, DeSl, IreneHemel, MaintBot, Fehrhart, and Finterly

Cited In


Homo sapiens


Inborn Errors of Metabolism (IEM) Pathways Rare Diseases


Pathway Ontology: thiamine metabolic pathway energy metabolic pathway


Label Type Compact Identifier
Citric acid cycle Pathway None
Pentose phosphate pathway Pathway wikipathways:WP134
Branched chain acylCoAs Metabolite None
DNA Metabolite chebi:16991
Glucose 6-phosphate Metabolite hmdb:HMDB0001401
isocitrate Metabolite chebi:16087
Glucose 1-phosphate Metabolite hmdb:HMDB0001586
succinate Metabolite chebi:30031
THTR1(SLC19A2) GeneProduct ensembl:ENSG00000117479
DHAP Metabolite chebi:16108
Branched chain amino acids Metabolite chebi:22918
Glycerol 3-phosphate Metabolite hmdb:HMDB0000126
TKT GeneProduct ensembl:ENSG00000163931
Branched chain keto acid dehydrogenase E1 Protein uniprot:A0A024R0K3
Oxaloacetate Metabolite chebi:30744
citrate Metabolite chebi:133748
Phospholipidpathway Pathway wikipathways:WP3933
pyruvate Metabolite chebi:15361
D-Glyceraldehyde 3-phosphate Metabolite hmdb:HMDB0001112
Thiamine pyrophosphate(TPP) Metabolite chebi:45931
serine Metabolite chebi:17822
THTR2(SLC19A3) GeneProduct ensembl:ENSG00000135917
Spingolipids pathway Pathway wikipathways:WP4142
SLC25A19 GeneProduct ensembl:ENSG00000125454
Acetyl-CoA Metabolite chebi:15351
Pyruvate dehydrogenase E1 GeneProduct ensembl:ENSG00000131828
BCKDK GeneProduct ensembl:ENSG00000103507
OGDH GeneProduct ensembl:ENSG00000105953
alpha-ketoglutarate Metabolite chebi:16810
D-Ribose 5-phosphate Metabolite hmdb:HMDB0001548
TPK1 GeneProduct ensembl:ENSG00000196511
TPP Metabolite chebi:45931
TPP Metabolite chebi:45931
TPP Metabolite chebi:45931
TPP Metabolite chebi:45931
TPP Metabolite chebi:45931
sphingolipids Metabolite chebi:26739
plasmalogens Metabolite None
phospholipids Metabolite chebi:16247
Thiamine monophosphate (TMP) Metabolite chebi:9533
thiamine Metabolite chebi:33283


  1. Rindi G, Laforenza U. Thiamine intestinal transport and related issues: recent aspects. Proc Soc Exp Biol Med. 2000 Sep;224(4):246–55. PubMed Europe PMC Scholia
  2. PubMed Europe PMC Scholia