Identification of a GPI-anchored type HDL-binding protein on human macrophages.
To identify the HDL3-binding proteins on human macrophages, we examined the involvement of GPI-anchored protein in the binding of HDL3, and tried to purify HDL3-binding protein. From membrane fractions of macrophages, we obtained 80- and 130-kDa HDL3-binding proteins by ligand blotting. Treatment of macrophages with phosphatidylinositol-specific phospholipase C (PI-PLC) significantly decreased the specific HDL3-binding in a dose-dependent manner. Furthermore, treatment with mannosamine, which blocks GPI-anchor formation, decreased specific HDL3-binding in a dose-dependent manner. PI-PLC treatment released from the cells the proteins with an M(r) of 80 kDa, which could also bind HDL3. PI-PLC as well as mannosamine treatment markedly reduced cholesterol efflux from macrophages in association with the decreased HDL-binding. Using HDL3-affinity chromatography, we purified 80-kDa GPI-anchored type HDL3-binding protein. In summary, we demonstrate the implication of 80-kDa GPI-anchored protein in the binding of HDL3 to human macrophages, which might have some role in reverse cholesterol transport.
Matsuyama
A
A
Department of Internal Medicine and Molecular Science, Graduate School of Medicine, Osaka University, Suita, Japan.
Yamashita
S
S
Sakai
N
N
Maruyama
T
T
Okuda
E
E
Hirano
K
K
Kihara
S
S
Hiraoka
H
H
Matsuzawa
Y
Y
D001665:Binding Sites / Q000187:drug effects; D001692:Biological Transport / Q000187:drug effects; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism; D002846:Chromatography, Affinity; D004305:Dose-Response Relationship, Drug; D017261:Glycosylphosphatidylinositols / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006595:Hexosamines / Q000494:pharmacology; D006801:Humans; D008024:Ligands; D008075:Lipoproteins, HDL / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000494:pharmacology; D008264:Macrophages / Q000737:chemistry* / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D015336:Molecular Probe Techniques; D008970:Molecular Weight; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D011485:Protein Binding / Q000187:drug effects; D013379:Substrate Specificity; D010738:Type C Phospholipases / Q000378:metabolism / Q000494:pharmacology
D002352:Carrier Proteins; D017261:Glycosylphosphatidylinositols; D006595:Hexosamines; D008024:Ligands; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D008565:Membrane Proteins; C032629:acetyl-LDL; C008322:mannosamine; D002784:Cholesterol; D010738:Type C Phospholipases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase