Sphingolipid and Glycolipid Biology

Sphingolipids are ubiquitous components of cell membranes, and are found in plants, animals, and fungi, as well as in some unicellular organisms and prokaryotes. Sphingolipids consist of a sphingoid long-chain base to which a fatty acid is attached at carbon 2, and a variety of polar and nonpolar head groups at C-1; glycosphingolipids are sphingolipids containing one or more sugar moieties in their head groups. Metabolic pathways have been determined for most sphingolipids, but little is known about how these pathways are regulated. Recent interest in sphingolipids and glycosphingolipids has focused largely on their roles in signaling events, with ceramide and sphingosine-1-phosphate the focus of particular attention. Sphingolipids also play vital roles in the formation and stability of membrane microdomains (rafts), and complex glycosphingolipids play roles in recognition. These lipids are also involved in disease pathology, and the pathways of sphingolipid metabolism, as well as the lipids themselves, have been implicated as possible therapeutic targets and agents.