Neutrophils promote the release of alpha-6-fucosyltransferase from blood platelets through the action of cathepsin G and elastase

Human blood platelets release alpha -6-fucosyltransferase during coagulatio n of blood or after stimulation with thrombin or other agonists that cause platelet activation (Antoniewicz et al., FEBS Lett. 244 (1989) 388-390). Ho wever, in the absence of neutrophils the thrombin-stimulated platelets rele ase only a small fraction of alpha -6-fucosyltransferase activity (Kosciela k et al., Acta Biochim. Polon. 42 (1995) 35-40). We show that the effect of neutrophils is reproduced by cathepsin G or (less efficiently) by elastase , the two enzymes that are released by neutrophils during coagulation of bl ood. We have also localized alpha -6-fucosyltransferase to membrane and alp ha -granule fractions of platelets that had been disrupted by nitrogen cavi tation. It is concluded that thrombin-activated neutrophils release catheps in G and elastase that promote degranulation of platelets and hence the sec retion of alpha -6-fucosyltransferase. (C) 2001 Societe francaise de biochi mie et biologie moleculaire/Editions scientifiques et medicales Elsevier SA S. All rights reserved.