title: Micrometric segregation of fluorescent membrane lipids: relevance for endogenous lipids and biogenesis in erythrocytes.
abstract: Micrometric membrane lipid segregation is controversial. We addressed this issue in attached erythrocytes and found that fluorescent boron dipyrromethene (BODIPY) analogs of glycosphingolipids (GSLs) [glucosylceramide (BODIPY-GlcCer) and monosialotetrahexosylganglioside (GM1BODIPY)], sphingomyelin (BODIPY-SM), and phosphatidylcholine (BODIPY-PC inserted into the plasma membrane spontaneously gathered into distinct submicrometric domains. GM1BODIPY domains colocalized with endogenous GM1 labeled by cholera toxin. All BODIPY-lipid domains disappeared upon erythrocyte stretching, indicating control by membrane tension. Minor cholesterol depletion suppressed BODIPY-SM and BODIPY-PC but preserved BODIPY-GlcCer domains. Each type of domain exchanged constituents but assumed fixed positions, suggesting self-clustering and anchorage to spectrin. Domains showed differential association with 4.1R versus ankyrin complexes upon antibody patching. BODIPY-lipid domains also responded differentially to uncoupling at 4.1R complexes [protein kinase C (PKC) activation] and ankyrin complexes (in spherocytosis, a membrane fragility disease). These data point to micrometric compartmentation of polar BODIPY-lipids modulated by membrane tension, cholesterol, and differential association to the two nonredundant membrane:spectrin anchorage complexes. Micrometric compartmentation might play a role in erythrocyte membrane deformability and fragility.
authors: CELL Unit, Division of Hematology-Oncology, de Duve Institute and Université Catholique de Louvain, Brussels, Belgium.
authors: Ludovic
authors: L
authors: D'Auria
authors: Marisa
authors: M
authors: Fenaux
authors: Paulina
authors: P
authors: Aleksandrowicz
authors: Patrick
authors: P
authors: Van Der Smissen
authors: Christophe
authors: C
authors: Chantrain
authors: Christiane
authors: C
authors: Vermylen
authors: Miikka
authors: M
authors: Vikkula
authors: Pierre J
authors: PJ
authors: Courtoy
authors: Donatienne
authors: D
authors: Tyteca
mesh_terms: D015153:Blotting, Western; D001896:Boron Compounds / Q000737:chemistry; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D002784:Cholesterol / Q000737:chemistry; D002855:Chromatography, Thin Layer; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D006028:Glycosphingolipids / Q000737:chemistry; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry; D006801:Humans; D008563:Membrane Lipids / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010713:Phosphatidylcholines / Q000737:chemistry; D013109:Sphingomyelins / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000494:pharmacology
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; C560998:BODIPY-PC; D001896:Boron Compounds; D006028:Glycosphingolipids; D006575:Heterocyclic Compounds, 3-Ring; D008563:Membrane Lipids; D010713:Phosphatidylcholines; D013109:Sphingomyelins; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D002784:Cholesterol