Glycosphingolipids biosynthetic pathway

Scheme 5. Various Glycosyltransfer Reactions Related to the Biosynthesis of Glycosphingolipids having Globo-series Sugar Chains. (Broken arrows indicate the hypothetical, biosynthetic pathway.)...

Glycosphingolipids (GSLs) are primarily synthesized in the endoplasmic reticulum (ER) and Golgi apparatus [24,25,26] and are internalized by endocytosis [27]. The known biosynthetic pathways of GSLs and gangliosides are depicted in O Fig. 1 and O Fig. 2, respectively. 

Mitochondria constantly undergo fission and fusion [48]. Thus, they demand a constant and well-regulated supply of GPL species for membrane integrity [49]. Moreover, it is well known that mitochondria also play a role in interorganelle trafficking of the intermediates and products of GPL biosynthetic pathways, Cer and cholesterol metabolism, and glycosphingolipid anabolism [49, 50]. For example, decarboxylation of PS species to generate PE species in mitochondria plays a vital role in mammals [51]. Furthermore, mitochondria possess a unique class of GPL (i.e., cardiolipin). 

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