Sphingosine
Encyclopedia
Sphingosine is an 18-carbon amino alcohol
with an unsaturated hydrocarbon chain, which forms a primary part of sphingolipid
s, a class of cell membrane
lipid
s that include sphingomyelin
, an important phospholipid
.
in vivo via two kinases, sphingosine kinase
type 1 and sphingosine kinase type 2. This leads to the formation of sphingosine-1-phosphate
, a potent signaling lipid
.
Sphingolipid metabolites, such as ceramide
, sphingosine and sphingosine-1-phosphate
, are lipid signaling
molecules involved in diverse cellular processes.
and serine
in a condensation required to yield dehydrosphingosine.
Dehydrosphingosine is then reduced by NADPH to dihydrosphingosine (sphinganine), and finally oxidized by FAD
to sphingosine.
There is no direct route of synthesis from sphinganine to sphingosine; it has to be acylated first to dihydroceramide, which is then dehydrogenated to ceramide. Sphingosine is formed via degradation of sphingolipid in the lysosome.
Amino alcohol
Amino alcohols are organic compounds that contain both an amine functional group and an alcohol functional group.-Common amino alcohols:* Ethanolamines* Heptaminol* Isoetarine* Norepinephrine* Propanolamines* Sphingosine...
with an unsaturated hydrocarbon chain, which forms a primary part of sphingolipid
Sphingolipid
Sphingolipids are a class of lipids containing a backbone of sphingoid bases, a set of aliphatic amino alcohols that includes sphingosine. They were discovered in brain extracts in the 1870s and were named for the mythological Sphinx because of their enigmatic nature. These compounds play...
s, a class of cell membrane
Cell membrane
The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...
lipid
Lipid
Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...
s that include sphingomyelin
Sphingomyelin
Sphingomyelin is a type of sphingolipid found in animal cell membranes, especially in the membranous myelin sheath that surrounds some nerve cell axons. It usually consists of phosphorylcholine and ceramide...
, an important phospholipid
Phospholipid
Phospholipids are a class of lipids that are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule is sphingomyelin, which is derived from...
.
Functions
Sphingosine can be phosphorylatedPhosphorylation
Phosphorylation is the addition of a phosphate group to a protein or other organic molecule. Phosphorylation activates or deactivates many protein enzymes....
in vivo via two kinases, sphingosine kinase
Sphingosine kinase
Sphingosine kinase is a conserved lipid kinase that catalyzes formation Sphingosine-1-phosphate from the precursor sphingolipid sphingosine. Sphingolipid metabolites, such as ceramide, sphingosine and sphingosine-1-phosphate, are lipid second messengers involved in diverse cellular processes. ...
type 1 and sphingosine kinase type 2. This leads to the formation of sphingosine-1-phosphate
Sphingosine-1-phosphate
Sphingosine-1-phosphate is a signaling sphingolipid. It is also referred to as a bioactive lipid mediator. Sphingolipids at large form a class of lipids characterized by a particular aliphatic aminoalcohol, which is sphingosine.-Production:...
, a potent signaling lipid
Lipid signaling
Lipid signaling, broadly defined, refers to any biological signaling event involving a lipid messenger that binds a protein target, such as a receptor, kinase or phosphatase, which in turn mediate the effects of these lipids on specific cellular responses...
.
Sphingolipid metabolites, such as ceramide
Ceramide
Ceramides are a family of lipid molecules. A ceramide is composed of sphingosine and a fatty acid. Ceramides are found in high concentrations within the cell membrane of cells. They are one of the component lipids that make up sphingomyelin, one of the major lipids in the lipid bilayer...
, sphingosine and sphingosine-1-phosphate
Sphingosine-1-phosphate
Sphingosine-1-phosphate is a signaling sphingolipid. It is also referred to as a bioactive lipid mediator. Sphingolipids at large form a class of lipids characterized by a particular aliphatic aminoalcohol, which is sphingosine.-Production:...
, are lipid signaling
Lipid signaling
Lipid signaling, broadly defined, refers to any biological signaling event involving a lipid messenger that binds a protein target, such as a receptor, kinase or phosphatase, which in turn mediate the effects of these lipids on specific cellular responses...
molecules involved in diverse cellular processes.
Synthesis
Sphingosine is synthesized from palmitoyl CoAPalmitoyl CoA
Palmitoyl CoA is an acyl-CoA thioester used in the biosynthesis of sphingosine:...
and serine
Serine
Serine is an amino acid with the formula HO2CCHCH2OH. It is one of the proteinogenic amino acids. By virtue of the hydroxyl group, serine is classified as a polar amino acid.-Occurrence and biosynthesis:...
in a condensation required to yield dehydrosphingosine.
FAD
In biochemistry, flavin adenine dinucleotide is a redox cofactor involved in several important reactions in metabolism. FAD can exist in two different redox states, which it converts between by accepting or donating electrons. The molecule consists of a riboflavin moiety bound to the phosphate...
to sphingosine.
There is no direct route of synthesis from sphinganine to sphingosine; it has to be acylated first to dihydroceramide, which is then dehydrogenated to ceramide. Sphingosine is formed via degradation of sphingolipid in the lysosome.