A Picture of the Biochemical Process
Submitted by: Ellen Deater Burns, Medical Liaison
“The following is excerpted from the website of Jeffrey Harmon, PhD, Professor and Chair of the Department of Pharmacology, Uniformed Services University of the Health Sciences. [http://www.usuhs.mil/pha/jharmon.html] I thought it was a fairly clear picture of the biochemical process.” —Ellen Deater Burns
Sphingolipids are a type of lipid, or fat, found in living cells, usually in the membrane surrounding cells. Sphingolipids are involved in maintaining the structural integrity of cell membranes, serve as intracellular and intercellular signaling molecules, and are highly enriched in lipid rafts (specialized membrane domains in cell walls enriched in certain lipids, cholesterol, and proteins) which are implicated in protein trafficking. The rate limiting step in sphingolipid biosynthesis is catalyzed by the enzyme serine palmitoyltransferase found in the endoplasmic reticulum (a network of tubules, vesicles and sacs that are interconnected and may serve specialized functions within the cell). Mutations in the gene encoding a sub-unit of this enzyme are responsible for the neurologic disorder Hereditary Sensory Neuropathy Type I (HSAN1), a disease selectively affecting peripheral sensory neurons.