WP4297 - Thiamine metabolic pathways - Homo sapiens

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)).