Sjölin C, Dahlgren C
Phagocyte Research Laboratory, Department of Medical Microbiology and Immunology, University of Göteborg, Sweden.
Biochim Biophys Acta. 1996 Jun 11;1281(2):227-34. doi: 10.1016/0005-2736(96)00018-1.
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.
一种中性粒细胞膜联蛋白I相关蛋白，在胞质蛋白转运至特定颗粒和分泌小泡/质膜后被检测到（Sjölin等人，(1994)《生物化学杂志》300, 325 - 330），已就其起源和细胞器结合特性进行了表征。膜联蛋白I相关蛋白是膜联蛋白I裂解的产物，这种裂解发生在膜联蛋白I转运至特定颗粒和分泌小泡/质膜的过程中，但膜联蛋白I转运至嗜天青颗粒时则不会发生。这种裂解需要钙离子，并且在存在特定颗粒或分泌小泡/质膜时会加速，但在存在嗜天青颗粒时则不会。我们得出结论，特定颗粒和分泌小泡/质膜的膜含有一种蛋白酶，它能够将膜联蛋白I裂解为一个截短的38 kDa片段，该片段保留了与这些细胞器结合的能力。嗜天青颗粒缺乏裂解膜联蛋白I的能力以及结合38 kDa片段的能力。这些发现可能暗示膜联蛋白I在不同中性粒细胞颗粒胞吐作用的差异调节中发挥作用。
