P-selectin is acylated with palmitic acid and stearic acid at cysteine 766 through a thioester linkage.
We report that the adhesion receptor P-selectin can be metabolically labeled with [3H]palmitic acid in human platelets. Analysis of alkaline methanolysis products from labeled protein demonstrated that the radioactivity associated with P-selectin was covalently bound palmitic acid. [3H]Palmitic acid was cleaved by hydroxylamine treatment at neutral pH and by reducing agents, indicating that acylation occurred through a thioester linkage. Both stearic acid and palmitic acid were detected by gas chromatography-mass spectrometry analysis of alkaline hydrolysates of purified P-selectin. Deletion or mutation of Cys766 eliminated [3H] palmitic acid labeling of P-selectin in transfected COS-7 cells. We conclude that the cytoplasmic domain of P-selectin is acylated at Cys766 through a thioester bond. Fatty acid acylation may regulate intracellular trafficking or other functions of P-selectin.
Fujimoto
T
T
W. K. Warren Medical Research Institute, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City 73104.
Stroud
E
E
Whatley
R E
RE
Prescott
S M
SM
Muszbek
L
L
Laposata
M
M
McEver
R P
RP
D000215:Acylation; D000595:Amino Acid Sequence; D015703:Antigens, CD / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D001792:Blood Platelets / Q000378:metabolism*; D003001:Cloning, Molecular; D003545:Cysteine; D004247:DNA / Q000097:blood / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D019007:P-Selectin; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000097:blood*; D010980:Platelet Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011499:Protein Processing, Post-Translational; D013229:Stearic Acids / Q000097:blood*; D014316:Tritium
D015703:Antigens, CD; D009838:Oligodeoxyribonucleotides; D019007:P-Selectin; D010169:Palmitic Acids; D010980:Platelet Membrane Glycoproteins; D013229:Stearic Acids; D014316:Tritium; D019308:Palmitic Acid; C031183:stearic acid; D004247:DNA; D003545:Cysteine