Polyunsaturated fatty acids alter sterol transbilayer domains in LM fibroblast plasma membrane.
Sterols are asymmetrically distributed between the leaflets of animal cell plasma membranes. Although transbilayer migration of sterols is extremely rapid, s to min, previous experimental manipulations have not altered their transmembrane steady-state distribution. However, the effect of polyunsaturated fatty acids has not been reported. When cultured in a lipid-free, chemically defined culture medium, LM fibroblasts do not synthesize polyunsaturated fatty acids but will incorporate polyunsaturated fatty acids into their plasma membranes if supplied in the medium. Sterol transbilayer distribution in LM plasma membranes was determined from quenching of fluorescence of dehydroergosterol by trinitrophenyl groups selectively attached to the exofacial leaflet. When cells are cultured in lipid-free media, 28.1% of the plasma membrane sterol is located in the exofacial (outside) leaflet. In contrast, when cells are cultured with linoleate- or linolenate-supplemented medium, 71.8% and 75.5% of the plasma membrane sterol is exofacial, respectively.
Sweet
W D
WD
Department of Pharmacology, Oral Roberts University School of Medicine, Tulsa, OK 74137-1247.
Schroeder
F
F
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D004875:Ergosterol / Q000031:analogs & derivatives / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D008051:Lipid Bilayers / Q000378:metabolism*; D051379:Mice; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013261:Sterols / Q000378:metabolism*; D014302:Trinitrobenzenesulfonic Acid / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000378:metabolism
D005231:Fatty Acids, Unsaturated; D008051:Lipid Bilayers; D013261:Sterols; C010905:dehydroergosterol; D014302:Trinitrobenzenesulfonic Acid; D000254:Sodium-Potassium-Exchanging ATPase; D004875:Ergosterol