Phosphatidylglucoside forms specific lipid domains on the outer leaflet of the plasma membrane.
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.
Murate
Motohide
M
RIKEN Advanced Science Institute, Saitama, Japan.
Hayakawa
Tomohiro
T
Ishii
Kumiko
K
Inadome
Hironori
H
Greimel
Peter
P
Watanabe
Masaki
M
Nagatsuka
Yasuko
Y
Ito
Kazuki
K
Ito
Yukishige
Y
Takahashi
Hiroshi
H
Hirabayashi
Yoshio
Y
Kobayashi
Toshihide
T
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
D004537:Eicosanoic Acids; D005963:Glucosylceramides; D020404:Glycerophospholipids; D008563:Membrane Lipids; D013109:Sphingomyelins; D013229:Stearic Acids; C429823:phosphatidylglucose; C031183:stearic acid; C094477:arachidic acid