| text |
Sphingolipids compose ?40% of the lipids of the plasma membrane and are also abundant in other endomembranes. There are three main types of sphingolipids: ceramides, sphingomyelins, and glycosphingolipids. Ceramides are the most simple sphingolipids, composed of only the sphingoid base and a fatty acid. Sphingomyelins are composed of a ceramide bound to a charged head group, usually phosphocholine. Glycosphingolipids are composed of a ceramide with attached mono- or oligosaccharide moieties. Sphingolipid biosynthesis starts in the endoplasmic reticulum (ER). L-serine is condensed with palmitoyl-CoA to generate a sphingoid long-chain base (LCB) that is reduced and then N-acylated to form ceramide. Ceramides are substrates for the production of complexs sphingolipids, including inositol phosphorylceramide (IPC), and glucosylceramide. Functional genomics of sphingolipid metabolism genes show that these molecules have essential functions in plant growth, development, and stress responses (Ishikawa et al., 2016).
|
