Preparing your results

Our searching services are busy right now. Your search will reload in five seconds.

Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Involvement of SNAP-23 and syntaxin 6 in human neutrophil exocytosis.

To understand the molecular basis of exocytosis in human neutrophils, the role of syntaxin 6 and SNAP-23 in neutrophil degranulation was examined. Human syntaxin 6 was cloned and identified as a 255-amino acid protein with a carboxy-terminal transmembrane region and two coiled-coil domains. Syntaxin 6 was localized mainly in the plasma membrane of human resting neutrophils, whereas SNAP-23 was located primarily in the mobilizable tertiary and specific granules. SNAP-23 was translocated to the cell surface, colocalizing with syntaxin 6, on neutrophil activation. In vitro binding studies established that SNAP-23 binds to syntaxin 6. Coimmunoprecipitation assays indicated that SNAP-23 interacts with syntaxin 6 in vivo, and this interaction was dramatically increased on neutrophil activation. Antibodies against SNAP-23 inhibited Ca(++) and GTP-gamma-S-induced exocytosis of CD67-enriched specific granules, but they hardly affected exocytosis of the CD63-enriched azurophilic granules, when introduced into electropermeabilized neutrophils. Anti-syntaxin 6 antibodies prevented exocytosis of both CD67- and CD63-enriched granules in electropermeabilized neutrophils. These data show that syntaxin 6 and SNAP-23 are involved in human neutrophil exocytosis, demonstrating that vesicle SNAP receptor-target SNAP receptor (v-SNARE- t-SNARE) interactions modulate neutrophil secretion. Syntaxin 6 acts as a target for secretion of specific and azurophilic granules, whereas SNAP-23 mediates specific granule secretion.

Pubmed ID: 11001914


  • Martín-Martín B
  • Nabokina SM
  • Blasi J
  • Lazo PA
  • Mollinedo F



Publication Data

October 1, 2000

Associated Grants


Mesh Terms

  • Amino Acid Sequence
  • Antibodies, Monoclonal
  • Antigens, CD
  • Antigens, CD63
  • Antigens, Neoplasm
  • Calcium
  • Carrier Proteins
  • Cell Adhesion Molecules
  • Cell Degranulation
  • Cell Membrane
  • Cell Membrane Permeability
  • Cloning, Molecular
  • Exocytosis
  • Fluorescent Antibody Technique
  • Guanosine 5'-O-(3-Thiotriphosphate)
  • Humans
  • Immunoblotting
  • Membrane Glycoproteins
  • Membrane Proteins
  • Microscopy, Confocal
  • Molecular Sequence Data
  • Neutrophils
  • Platelet Membrane Glycoproteins
  • Qa-SNARE Proteins
  • Qb-SNARE Proteins
  • Qc-SNARE Proteins
  • RNA, Messenger
  • Reverse Transcriptase Polymerase Chain Reaction
  • Subcellular Fractions