Schematic view of the GSL metabolism pathways

Schematic view of the GSL metabolism pathways. The synthesis of GSLs and gangliosides progress stepwise and are catalyzed by membranous glycosyltransferases in the ER or Golgi apparatus (see text). The degradation reactions are also sequential and occur within the lysosomes by various hydrolases. The black arrows show the synthesis pathway in the ER and Golgi and the green arrows show the degradation pathway in the lysosome. The enzymes in o-, a-, b-, and c-ganglioside series are numbered: 1. GM2/GD2/GA2/GT2-synthase (β-1,4-N-acetyl-galactosaminyltransferase, GalNacT), 2. GA1/GM1a/GD1b/GT1c-synthase (UDP-Gal:βGalNAc β-1,3-galactosyltransferase), 3. sialyltransferase IV, 4. sialyltransferase V, 5. sialyltransferase VII, 6. sialidase. Abbreviations: 3-KSR (3-ketosphinganine reductase), Sk (sphingosine kinase), Sa1P (sphinganine 1-phosphate), S1P (sphingosine 1-phosphate), S1-P Pase (sphingosine 1-phosphate phosphatase), (Sa) N-ACT (sphinganine N-acyltransferase), DHCerS (dihydroceramide desaturase), CerS (ceramide synthase, also called longevity assurance genes), SMS (sphingomyelin synthase), GT3 synthase (α-N-acetyl-neuraminide α-2,8- sialyltransferase). The chemical structures are adapted from (, , , –) and http://www.cybercolloids.net/library/sugars/hexoses.php. Nomenclature of the enzymes and protein are from IUBMB (http://www.chem.qmul.ac.uk/iubmb/enzyme) (, , ).

Publication

Multi-system disorders of glycosphingolipid and ganglioside metabolism. (2010) You-Hai Xu, et al. J Lipid Res. 2010 Jul;51(7):1643-1675. Figure: F1. All organisms Drosophila melanogaster Homo sapiens

Disease mentions