English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/3540
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:


Asymmetric Addition of Ceramides but not Dihydroceramides Promotes Transbilayer (Flip-Flop) Lipid Motion in Membranes

AuthorsContreras, F. Xabier; Basañez, Gorka; Alonso, Alicia; Herrmann, Andreas; Goñi, Félix M.
Issue DateJan-2005
PublisherBiophysical Society
CitationBiophys J. 2005 January; 88(1): 348–359
AbstractTransbilayer lipid motion in membranes may be important in certain physiological events, such as ceramide signaling. In this study, the transbilayer redistribution of lipids induced either by ceramide addition or by enzymatic ceramide generation at one side of the membrane has been monitored using pyrene-labeled phospholipid analogs. When added in organic solution to preformed liposomes, egg ceramide induced transbilayer lipid motion in a dose-dependent way. Short-chain (C6 and C2) ceramides were less active than egg ceramide, whereas dihydroceramides or dioleoylglycerol were virtually inactive in promoting flip-flop. The same results (either positive or negative) were obtained when ceramides, dihydroceramides, or diacylglycerols were generated in situ through the action of a sphingomyelinase or of a phospholipase C. The phenomenon was dependent on the bilayer lipid composition, being faster in the presence of lipids that promote inverted phase formation, e.g., phosphatidylethanolamine and cholesterol; and, conversely, slower in the presence of lysophosphatidylcholine, which inhibits inverted phase formation. Transbilayer motion was almost undetectable in bilayers composed of pure phosphatidylcholine or pure sphingomyelin. The use of pyrene-phosphatidylserine allowed detection of flip-flop movement induced by egg ceramide in human red blood cell membranes at a rate comparable to that observed in model membranes. The data suggest that when one membrane leaflet becomes enriched in ceramides, they diffuse toward the other leaflet. This is counterbalanced by lipid movement in the opposite direction, so that net mass transfer between monolayers is avoided. These observations may be relevant to the physiological mechanism of transmembrane signaling via ceramides.
DescriptionCopyright © by Biophysical Society. Final full-text version of the paper available at: http://www.biophysj.org/cgi/content/abstract/88/1/348
Appears in Collections:(UBF) Artículos
Files in This Item:
File Description SizeFormat 
picrender.pdf172,11 kBAdobe PDFThumbnail
Show full item record
Review this work

Related articles:

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.