Journal of Chemical Biology | |
Enhancement of the Ca2+-triggering steps of native membrane fusion via thiol-reactivity | |
David M. Brandman2  Kendra L. Furber1  Jens R. Coorssen3  | |
[1] Hotchkiss Brain Institute, University of Calgary Faculty of Medicine, Calgary, AB T2N 4N1 Canada;Department of Physiology and Biophysics, University of Calgary Faculty of Medicine, Calgary, AB T2N 4N1 Canada;Molecular Physiology, School of Medicine, University of Western Sydney, Bldg. 30, Campbelltown, NSW 1797 Australia | |
关键词: Membrane fusion; Calcium; Strontium; Thiol reactivity; Exocytosis; Vesicle; | |
DOI : 10.1007/s12154-008-0013-3 | |
学科分类:分子生物学,细胞生物学和基因 | |
来源: Springer | |
【 摘 要 】
Ca2+-triggered membrane fusion is the defining step of exocytosis. Isolated urchin cortical vesicles (CV) provide a stage-specific preparation to study the mechanisms by which Ca2+ triggers the merger of two apposed native membranes. Thiol-reactive reagents that alkylate free sulfhydryl groups on proteins have been consistently shown to inhibit triggered fusion. Here, we characterize a novel effect of the alkylating reagent iodoacetamide (IA). IA was found to enhance the kinetics and Ca2+ sensitivity of both CV-plasma membrane and CV–CV fusion. If Sr2+, a weak Ca2+ mimetic, was used to trigger fusion, the potentiation was even greater than that observed for Ca2+, suggesting that IA acts at the Ca2+-sensing step of triggered fusion. Comparison of IA to other reagents indicates that there are at least two distinct thiol sites involved in the underlying fusion mechanism: one that regulates the efficiency of fusion and one that interferes with fusion competency.
【 授权许可】
Unknown
【 预 览 】
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