title: Phosphatidylglucoside forms specific lipid domains on the outer leaflet of the plasma membrane.
abstract: Phosphatidylglucoside (PtdGlc) is a recently discovered unique glycophospholipid involved in granulocytic differentiation of human promyelocytic leukemia cell line HL60 and in astrocytic differentiation in developing rodent brains. Using a PtdGlc-specific monoclonal antibody in immunofluorescence and immunoelectron microscopy, we showed that PtdGlc forms distinct lipid domains on the outer leaflet of the plasma membrane of HL60 cells and the human alveolar epithelial cell line, A549. Similar to glycosphingolipid, glucosylceramide (GlcCer), the natural form of PtdGlc exhibited a high main phase transition temperature in differential scanning calorimetry (DSC). However, unlike GlcCer, PtdGlc did not exhibit a large difference in the main phase transition temperature between the heating and cooling scans. DSC further indicated that GlcCer, but not PtdGlc, was miscible with sphingomyelin. In addition, DSC and small-angle X-ray scattering (SAXS) experiments revealed that PtdGlc was poorly miscible with phosphatidylcholine. Our results suggest that the lack of tight intermolecular interaction excludes PtdGlc from other lipid domains on the plasma membrane.
authors.affiliation: RIKEN Advanced Science Institute, Saitama, Japan.
authors.forename: Motohide
authors.initials: M
authors.lastname: Murate
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Kumiko
authors.initials: K
authors.lastname: Ishii
authors.forename: Hironori
authors.initials: H
authors.lastname: Inadome
authors.forename: Peter
authors.initials: P
authors.lastname: Greimel
authors.forename: Masaki
authors.initials: M
authors.lastname: Watanabe
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Nagatsuka
authors.forename: Kazuki
authors.initials: K
authors.lastname: Ito
authors.forename: Yukishige
authors.initials: Y
authors.lastname: Ito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hirabayashi
authors.forename: Toshihide
authors.initials: T
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D002152:Calorimetry, Differential Scanning; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism*; D004537:Eicosanoic Acids / Q000737:chemistry / Q000378:metabolism; D005963:Glucosylceramides / Q000737:chemistry / Q000378:metabolism; D020404:Glycerophospholipids / Q000737:chemistry* / Q000378:metabolism*; D018922:HL-60 Cells; D006801:Humans; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism*; D051379:Mice; D018613:Microscopy, Confocal; D053838:Scattering, Small Angle; D013109:Sphingomyelins / Q000737:chemistry / Q000378:metabolism; D013229:Stearic Acids / Q000737:chemistry / Q000378:metabolism; D013552:Swine; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D004537:Eicosanoic Acids; D005963:Glucosylceramides; D020404:Glycerophospholipids; D008563:Membrane Lipids; D013109:Sphingomyelins; D013229:Stearic Acids; C429823:phosphatidylglucose; C031183:stearic acid; C094477:arachidic acid