Stabilin-1 localizes to endosomes and the trans-Golgi network in human macrophages and interacts with GGA adaptors

J Leukoc Biol. 2004 Dec;76(6):1151-61. doi: 10.1189/jlb.0504300. Epub 2004 Sep 2.

Abstract

Stabilin-1 and stabilin-2 constitute a novel family of fasciclin domain-containing hyaluronan receptor homologues recently described by us. Whereas stabilin-1 is expressed in sinusoidal endothelial cells and in macrophages in vivo, stabilin-2 is absent from the latter. In the present study, we analyzed the subcellular distribution of stabilin-1 in primary human macrophages. Using flow cytometry, expression of stabilin-1 was demonstrated on the surface of interleukin-4/dexamethasone-stimulated macrophages (MPhi2). By immunofluorescence and confocal microscopy, we established that stabilin-1 is preferentially localized in early endosome antigen-1-positive early/sorting endosomes and in recycling endosomes identified by transferrin endocytosis. Association of stabilin-1 was infrequently seen with p62 lck ligand-positive late endosomes and with CD63-positive lysosomes but not in lysosome-associated membrane protein-1-positive lysosomes. Stabilin-1 was also found in the trans-Golgi network (TGN) but not in Golgi stack structures. Glutathione S-transferase pull-down assay revealed that the cytoplasmic tail of stabilin-1 but not stabilin-2 binds to recently discovered Golgi-localized, gamma-ear-containing, adenosine 5'-diphosphate-ribosylation factor-binding (GGA) adaptors GGA1, GGA2, and GGA3 long, mediating traffic between Golgi and endosomal/lysosomal compartments. Stabilin-1 did not bind to GGA3 short, which lacks a part of the Vps27p/Hrs/STAM domain. Deletion of DDSLL and LL amino acid motifs resulted in decreased binding of stabilin-1 with GGAs. A small portion of stabilin-1 colocalized with GGA2 and GGA3 in the TGN in MPhi2. Treatment with brefeldin A resulted in accumulation of stabilin-1 in the TGN. Our results suggest that stabilin-1 is involved in the GGA-mediated sorting processes at the interface of the biosynthetic and endosomal pathways; similarly to other GGA-interacting proteins, stabilin-1 may thus function in endocytic and secretory processes of human macrophages.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADP-Ribosylation Factors / immunology
  • ADP-Ribosylation Factors / metabolism*
  • Adaptor Proteins, Vesicular Transport / immunology
  • Adaptor Proteins, Vesicular Transport / metabolism*
  • Amino Acid Motifs / immunology
  • Antigens, CD / immunology
  • Brefeldin A / pharmacology
  • Carrier Proteins / immunology
  • Carrier Proteins / metabolism
  • Cell Adhesion Molecules, Neuronal / immunology
  • Cell Adhesion Molecules, Neuronal / metabolism*
  • Cell Compartmentation / drug effects
  • Cell Compartmentation / immunology
  • Cells, Cultured
  • Dexamethasone / pharmacology
  • Endocytosis / drug effects
  • Endocytosis / physiology
  • Endosomes / drug effects
  • Endosomes / immunology
  • Endosomes / metabolism*
  • Flow Cytometry
  • Humans
  • Interleukin-4 / pharmacology
  • Lysosomal Membrane Proteins
  • Macrophages / drug effects
  • Macrophages / immunology
  • Macrophages / metabolism*
  • Membrane Glycoproteins / immunology
  • Membrane Glycoproteins / metabolism
  • Platelet Membrane Glycoproteins / immunology
  • Protein Binding / physiology
  • Protein Structure, Tertiary / physiology
  • Protein Transport / drug effects
  • Protein Transport / immunology
  • Receptors, Immunologic / immunology
  • Receptors, Lymphocyte Homing
  • Signal Transduction / drug effects
  • Signal Transduction / immunology
  • Tetraspanin 30
  • Transferrin / metabolism
  • trans-Golgi Network / drug effects
  • trans-Golgi Network / immunology*
  • trans-Golgi Network / metabolism

Substances

  • Adaptor Proteins, Vesicular Transport
  • Antigens, CD
  • CD63 protein, human
  • Carrier Proteins
  • Cell Adhesion Molecules, Neuronal
  • GGA adaptor proteins
  • GGA2 protein, human
  • LAMP1 protein, human
  • Lysosomal Membrane Proteins
  • Membrane Glycoproteins
  • Platelet Membrane Glycoproteins
  • Receptors, Immunologic
  • Receptors, Lymphocyte Homing
  • STAB1 protein, human
  • Tetraspanin 30
  • Transferrin
  • p62 natural killer cell receptor
  • Brefeldin A
  • Interleukin-4
  • Dexamethasone
  • ADP-Ribosylation Factors