Ceramide in Stem Cell Differentiation and Embryo Development: Novel Functions of a Topological Cell-Signaling Lipid and the Concept of Ceramide Compartments

Figure 1

Structure of ceramide and its derivatives. (a) Natural derivatives of ceramide. All of the sphingolipids are derived from the condensation reaction of serine with palmitoyl-CoA, which is followed by reduction, acylation, and desaturation reactions to yield ceramide. In addition to the derivatives shown, glucosyl- or galactosylceramide and ceramide-1-phosphate are important structural and cell-signaling lipids, in particular for myelin formation and inflammation. (b) Synthetic analog of ceramide. The polar serine head group is preserved in ceramide and many sphingolipid analogs (only one analog (S18) is shown here). This minimal structural motif is composed of two hydroxyl groups β-positioned to an amino group or an imino group, which is linked to a hydrocarbon chain (dashed box, S18 or N-oleyl serinol is a derivative of 2-amino 1,3-propanediol).