title: Stabilin-1 localizes to endosomes and the trans-Golgi network in human macrophages and interacts with GGA adaptors.
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.
authors.affiliation: Department of Dermatology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167 Mannheim, Germany. julia.kzhyshkowska@haut.ma.uni-heidelberg.de
authors.forename: Julia
authors.initials: J
authors.lastname: Kzhyshkowska
authors.forename: Alexei
authors.initials: A
authors.lastname: Gratchev
authors.forename: Jan-Henning
authors.initials: JH
authors.lastname: Martens
authors.forename: Olga
authors.initials: O
authors.lastname: Pervushina
authors.forename: Srinivas
authors.initials: S
authors.lastname: Mamidi
authors.forename: Sophie
authors.initials: S
authors.lastname: Johansson
authors.forename: Kai
authors.initials: K
authors.lastname: Schledzewski
authors.forename: Berit
authors.initials: B
authors.lastname: Hansen
authors.forename: Xiangyuan
authors.initials: X
authors.lastname: He
authors.forename: Jordan
authors.initials: J
authors.lastname: Tang
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Nakayama
authors.forename: Sergij
authors.initials: S
authors.lastname: Goerdt
mesh_terms: D020727:ADP-Ribosylation Factors / Q000276:immunology / Q000378:metabolism*; D033942:Adaptor Proteins, Vesicular Transport / Q000276:immunology / Q000378:metabolism*; D020816:Amino Acid Motifs / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology; D020126:Brefeldin A / Q000494:pharmacology; D002352:Carrier Proteins / Q000276:immunology / Q000378:metabolism; D015816:Cell Adhesion Molecules, Neuronal / Q000276:immunology / Q000378:metabolism*; D002451:Cell Compartmentation / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology; D011992:Endosomes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D015847:Interleukin-4 / Q000494:pharmacology; D051907:Lysosomal Membrane Proteins; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism; D010980:Platelet Membrane Glycoproteins / Q000276:immunology; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D021381:Protein Transport / Q000187:drug effects / Q000276:immunology; D011971:Receptors, Immunologic / Q000276:immunology; D016201:Receptors, Lymphocyte Homing; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology; D060149:Tetraspanin 30; D014168:Transferrin / Q000378:metabolism; D021601:trans-Golgi Network / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D052118:Lysosomal-Associated Membrane Protein 1
chemical_list: D020727:ADP-Ribosylation Factors; D033942:Adaptor Proteins, Vesicular Transport; D015703:Antigens, CD; D020126:Brefeldin A; D002352:Carrier Proteins; D015816:Cell Adhesion Molecules, Neuronal; D003907:Dexamethasone; D015847:Interleukin-4; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D010980:Platelet Membrane Glycoproteins; D011971:Receptors, Immunologic; D016201:Receptors, Lymphocyte Homing; D060149:Tetraspanin 30; D014168:Transferrin; C554586:CD63 protein, human; C407306:GGA adaptor proteins; C405944:GGA2 protein, human; C489116:LAMP1 protein, human; D052118:Lysosomal-Associated Membrane Protein 1; C449926:STAB1 protein, human; C431712:p62 natural killer cell receptor