title: Diverse effects of different neutrophil organelles on truncation and membrane-binding characteristics of annexin I.
abstract: A neutrophil annexin I-related protein, detected after translocation of cytosolic proteins to specific granules and secretory vesicles/plasma membrane (Sjölin et al. (1994) Biochem. J. 300, 325-330), has been characterized with respect to origin and organelle-binding properties. The annexin I-related protein is formed as a result of annexin I cleavage, and this occurs during translocation of annexin I to the specific granules and secretory vesicles/plasma membrane, but not when annexin I is translocated to azurophil granules. The cleavage required calcium and it was facilitated in the presence of specific granules or secretory vesicles/plasma membrane, but not in the presence of azurophil granules. We conclude that the membranes of specific granules and secretory vesicles/plasma membrane contain a protease which is able to cleave annexin I into a truncated 38 kDa fragment, which retains the ability to bind to these organelles. The azurophil granules lack the capacity to cleave annexin I as well as the ability to bind the 38 kDa fragment. These findings may implicate a role for annexin I in the divergent regulation of exocytosis of the different neutrophil granules.
authors.affiliation: Phagocyte Research Laboratory, Department of Medical Microbiology and Immunology, University of Göteborg, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Sjölin
authors.forename: C
authors.initials: C
authors.lastname: Dahlgren
mesh_terms: D017305:Annexin A1 / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism*; D003594:Cytoplasmic Granules / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D009504:Neutrophils / Q000648:ultrastructure*; D015388:Organelles / Q000378:metabolism*
chemical_list: D017305:Annexin A1; D010450:Endopeptidases; D002118:Calcium