Identification of N-acylphosphatidylserine molecules in eukaryotic cells.
While profiling the lipidome of the mouse brain by mass spectrometry, we discovered a novel family of N-acylphosphatidylserine (N-acyl-PS) molecules. These N-acyl-PS species were enriched by DEAE-cellulose column chromatography, and they were then characterized by accurate mass measurements, tandem mass spectrometry, liquid chromatography/mass spectrometry, and comparison to an authentic standard. Mouse brain N-acyl-PS molecules are heterogeneous and constitute about 0.1% of the total lipid. In addition to various ester-linked fatty acyl chains on their glycerol backbones, the complexity of the N-acyl-PS series is further increased by the presence of diverse amide-linked N-acyl chains, which include saturated, monounsaturated, and polyunsaturated species. N-Acyl-PS molecular species were also detected in the lipids of pig brain, mouse RAW264.7 macrophage tumor cells, and yeast, but not Escherichia coli. N-Acyl-PSs may be biosynthetic precursors of N-acylserine molecules, such as the recently reported signaling lipid N-arachidonoylserine from bovine brain. We suggest that a phospholipase D might cleave N-acyl-PS to generate N-acylserine, in analogy to the biosynthesis of the endocannabinoid N-arachidonoylethanolamine (anadamide) from N-arachidonoylphosphatidylethanolamine.
Guan
Ziqiang
Z
Department of Biochemistry, Duke University Medical Center, P.O. Box 3711, Durham, North Carolina 27710, USA.
Li
Shengrong
S
Smith
Dale C
DC
Shaw
Walter A
WA
Raetz
Christian R H
CR
D000818:Animals; D001921:Brain / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D002853:Chromatography, Liquid; D005057:Eukaryotic Cells / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D008055:Lipids / Q000737:chemistry / Q000302:isolation & purification; D013058:Mass Spectrometry; D051379:Mice; D015394:Molecular Structure; D010718:Phosphatidylserines / Q000737:chemistry* / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D013552:Swine; D053719:Tandem Mass Spectrometry
D005227:Fatty Acids; D008055:Lipids; D010718:Phosphatidylserines; D010739:Phospholipase D