EC Number   |
General Information |
Reference |
|---|
   2.7.8.B14 | evolution |
insect-specific CPE synthase belongs to a novel branch of CDP-alcohol phosphotransferases with unique membrane topology. CPE synthase constitutes a new branch within the CDP-alcohol phosphotransferase superfamily with homologues in Arthropoda (insects, spiders, mites, scorpions), Cnidaria (Hydra, sea anemones), and Mollusca (oysters) but not in most other animal phyla. The enzyme resides in the Golgi complex with its active site facing the lumen, contrary to the membrane topology of other CDPalcohol phosphotransferases |
738578 |
| 2.7.8.B14 | malfunction |
depletion of dCCS4 caused a major (about 60%) reduction in CPES activity. When incubated with CDP-[14C]Eth in the presence of Mn2+ ions, lysates of dCCS4-depleted cells synthesize only a minor (about 25%) fraction of the radiolabeled CPE formed in lysates of control (dsGFP-treated) cells. In addition, loss of dCCS4 causes a substantial drop in de novo synthesis of CPE, accompanied by a defect in cell growth |
738578 |
| 2.7.8.B14 | metabolism |
ceramide phosphoethanolamine (CPE) is the principal membrane sphingolipid. The corresponding CPE synthase shares mechanistic features with enzymes mediating phospholipid biosynthesis via the Kennedy pathway, e.g. EC 2.7.8.2. Drosophila lacks the phosphocholine-containing sphingomyelin (SM) found in mammalian membranes and instead synthesizes ceramide phosphoethanolamine (CPE). SMS2, EC 2.7.8.27, is a bifunctional enzyme that produces both SM and CPE, SMS2 likely accounts for the plasma membrane-resident CPE synthase activity |
738578 |
| 2.7.8.B14 | physiological function |
CDP-ethanolamine:ceramide ethanolamine phosphotransferase is the enzyme responsible for bulk production of ceramide phosphoethanolamine (CPE) in Drosophila. The smaller crosssectional area of the phosphoethanolamine headgroup in CPE allows a closer contact between these molecules in comparison with SM, promoting membrane viscosity. Contrary to sphingomyelin, CPE does not interact favorably with cholesterol and fails to form sterol-rich domains in model bilayers. The addition of CDP-Eth to lysates of HeLa cells expressing dCCS4 caused a dramatic increase in NBD-CPE formation. Drosophila S2 cells require dCCS4 for CDP-Eth-dependent CPE production and growth |
738578 |
