Rizo Josep, Chen Xiaocheng, Araç Demet
Departments of Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
Trends Cell Biol. 2006 Jul;16(7):339-50. doi: 10.1016/j.tcb.2006.04.006. Epub 2006 May 12.
SNARE proteins and synaptotagmin are key components of the complex machinery that controls Ca(2+)-triggered neurotransmitter release but their mechanisms of action are under debate. Recent research has shed light on which biochemical and/or biophysical properties underlie SNARE and synaptotagmin function. SNARE proteins most likely have a role in membrane fusion owing to their ability to bring the synaptic vesicle and plasma membranes together and to perturb lipid bilayers through their transmembrane regions. Synaptotagmin acts as a Ca(2+) sensor and might cooperate with the SNAREs in accelerating fusion by binding simultaneously to the two membranes. However, recent research has strongly challenged the validity of models proposing that the SNAREs (with or without synaptotagmin) constitute "minimal membrane fusion machineries" and has emphasized the essential nature of other proteins for exocytosis. Understanding the functions of these proteins will be crucial to reach a faithful description of the mechanisms of membrane fusion and neurotransmitter release.
SNARE蛋白和突触结合蛋白是控制钙离子触发神经递质释放的复杂机制的关键组成部分，但其作用机制仍存在争议。最近的研究揭示了SNARE蛋白和突触结合蛋白功能背后的生化和/或生物物理特性。SNARE蛋白很可能在膜融合中发挥作用，因为它们能够使突触小泡膜和质膜靠近，并通过其跨膜区域扰乱脂质双层。突触结合蛋白作为钙离子传感器，可能通过同时结合两个膜与SNARE蛋白协同作用来加速融合。然而，最近的研究强烈质疑了认为SNARE蛋白（无论有无突触结合蛋白）构成“最小膜融合机制”的模型的有效性，并强调了其他蛋白质在胞吐作用中的本质重要性。了解这些蛋白质的功能对于准确描述膜融合和神经递质释放机制至关重要。
