Identification of a GPI-anchored type HDL-binding protein on human macrophages

Biochem Biophys Res Commun. 2000 Jun 16;272(3):864-71. doi: 10.1006/bbrc.2000.2855.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites / drug effects
  • Biological Transport / drug effects
  • Carrier Proteins / antagonists & inhibitors
  • Carrier Proteins / chemistry
  • Carrier Proteins / isolation & purification*
  • Carrier Proteins / metabolism*
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Cholesterol / metabolism
  • Chromatography, Affinity
  • Dose-Response Relationship, Drug
  • Glycosylphosphatidylinositols / antagonists & inhibitors
  • Glycosylphosphatidylinositols / metabolism*
  • Hexosamines / pharmacology
  • Humans
  • Ligands
  • Lipoproteins, HDL / antagonists & inhibitors
  • Lipoproteins, HDL / metabolism*
  • Lipoproteins, LDL / pharmacology
  • Macrophages / chemistry*
  • Macrophages / cytology
  • Macrophages / drug effects
  • Macrophages / metabolism
  • Membrane Proteins / antagonists & inhibitors
  • Membrane Proteins / chemistry
  • Membrane Proteins / isolation & purification*
  • Membrane Proteins / metabolism
  • Molecular Probe Techniques
  • Molecular Weight
  • Phosphatidylinositol Diacylglycerol-Lyase
  • Phosphoinositide Phospholipase C
  • Protein Binding / drug effects
  • Substrate Specificity
  • Type C Phospholipases / metabolism
  • Type C Phospholipases / pharmacology

Substances

  • Carrier Proteins
  • Glycosylphosphatidylinositols
  • Hexosamines
  • Ligands
  • Lipoproteins, HDL
  • Lipoproteins, LDL
  • Membrane Proteins
  • acetyl-LDL
  • mannosamine
  • Cholesterol
  • Type C Phospholipases
  • Phosphoinositide Phospholipase C
  • Phosphatidylinositol Diacylglycerol-Lyase