Glucosylceramide

Glycosphingolipids (GSLs) are ubiquitous components of eukaryotic cell membranes. GSLs are synthesized by sequential addition of saccharides to the hydroxyl group at the C-1 position of the ceramide (Cer) backbone. GSLs are mainly located in the extracellular leaflet of the plasma membrane, where they are involved in several functions such as cell-to-cell interaction and recognition. Glucosylceramide (GlcCer), one of the simplest GSLs, is widely distributed in mammalian tissues. GlcCer is formed at the cytosolic leaflet of Golgi apparatus by glycosylation of Cer by GlcCer synthase (GCS). After its synthesis, GlcCer is transported to the luminal side of the Golgi apparatus where is converted into more complex GSLs, or transported by FAPP2 (4-phosphate adaptor protein-2) to the cytoplasmic leaflet of the plasma membrane (PM) or of the endoplasmic reticulum (ER). In the PM, GlcCer may remain on the cytoplasmic leaflet or translocate to the cell surface.