Role of vesicle-associated membrane protein-2, through Q-soluble N-ethylmaleimide-sensitive factor attachment protein receptor/R-soluble N-ethylmaleimide-sensitive factor attachment protein receptor interaction, in the exocytosis of specific and tertiary granules of human neutrophils.
We have examined the role of the R-soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) synaptobrevin-2/vesicle-associated membrane protein (VAMP)-2 in neutrophil exocytosis. VAMP-2, localized in the membranes of specific and gelatinase-containing tertiary granules in resting human neutrophils, resulted translocated to the cell surface following neutrophil activation under experimental conditions that induced exocytosis of specific and tertiary granules. VAMP-2 was also found on the external membrane region of granules docking to the plasma membrane in activated neutrophils. Specific Abs against VAMP-2 inhibited Ca(2+) and GTP-gamma-S-induced exocytosis of CD66b-enriched specific and tertiary granules, but did not affect exocytosis of CD63-enriched azurophilic granules, in electropermeabilized neutrophils. Tetanus toxin disrupted VAMP-2 and inhibited exocytosis of tertiary and specific granules. Activation of neutrophils led to the interaction of VAMP-2 with the plasma membrane Q-SNARE syntaxin 4, and anti-syntaxin 4 Abs inhibited exocytosis of specific and tertiary granules in electropermeabilized neutrophils. Immunoelectron microscopy showed syntaxin 4 on the plasma membrane contacting with docked granules in activated neutrophils. These data indicate that VAMP-2 mediates exocytosis of specific and tertiary granules, and that Q-SNARE/R-SNARE complexes containing VAMP-2 and syntaxin 4 are involved in neutrophil exocytosis.
Mollinedo
Faustino
F
Centro de Investigación del Cáncer, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Cientificas-Universidad de Salamanca, Spain. fmollin@usal.es
Martín-Martín
Belén
B
Calafat
Jero
J
Nabokina
Svetlana M
SM
Lazo
Pedro A
PA
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD; D000951:Antigens, Neoplasm / Q000378:metabolism; D001120:Arginine; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000276:immunology; D017124:Conserved Sequence; D003594:Cytoplasmic Granules / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure; D018274:Electroporation; D005089:Exocytosis / Q000276:immunology*; D058851:GPI-Linked Proteins; D005973:Glutamine; D006801:Humans; D007399:Interphase / Q000276:immunology; D008565:Membrane Proteins / Q000145:classification / Q000276:immunology / Q000378:metabolism* / Q000502:physiology* / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D018375:Neutrophil Activation / Q000276:immunology; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism* / Q000648:ultrastructure; D050765:Qa-SNARE Proteins; D050683:R-SNARE Proteins; D050600:SNARE Proteins; D012995:Solubility; D013744:Tetanus Toxin / Q000494:pharmacology; D033921:Vesicular Transport Proteins
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000951:Antigens, Neoplasm; C504120:CEACAM8 protein, human; D015815:Cell Adhesion Molecules; D058851:GPI-Linked Proteins; D008565:Membrane Proteins; D050765:Qa-SNARE Proteins; D050683:R-SNARE Proteins; D050600:SNARE Proteins; D013744:Tetanus Toxin; D033921:Vesicular Transport Proteins; D005973:Glutamine; D001120:Arginine