Granulocyte exocytosis is proposed to be critically dependent on the interaction of soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptors (SNAREs) located on granules/vesicles (v-SNAREs) and plasma membrane (t-SNAREs). Previous studies indicated that the v-SNARE, vesicle-associated membrane protein (VAMP)-2, as well as t-SNAREs (SNAP-23, syntaxin-4 and -6) are implicated in exocytosis from human granulocytes. Vesicle-associated membrane proteins-7 and -8 have been implicated in endosome/lysosome trafficking, however, their role in granulocyte exocytosis remains obscure.
Pulmonary Research Group, Department of Medicine, University of Alberta, Edmonton, AB, Canada, and Department of Medicine and Immunology, Mayo Clinic, Rochester, MN, USA.