Fasshauer Dirk
Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.
Biochim Biophys Acta. 2003 Aug 18;1641(2-3):87-97. doi: 10.1016/s0167-4889(03)00090-9.
Eukaryotic cells distribute materials among intracellular organelles and secrete into the extracellular space through cargo-loaded vesicles. A concluding step during vesicular transport is the fusion of a transport vesicle with a target membrane. SNARE proteins are essential for all vesicular fusion steps, thus they possibly comprise a conserved membrane fusion machinery. According to the "zipper" model, they assemble into stable membrane-bridging complexes that gradually bring membranes in juxtaposition. Hence, complex formation may provide the necessary energy for overcoming the repulsive forces between two membranes. During the last years, detailed structural and functional studies have extended the evidence that SNAREs are mostly in accord with the zipper model. Nevertheless, it remains unclear whether SNARE assembly between membranes directly leads to the merger of lipid bilayers.
真核细胞在细胞内细胞器之间分配物质，并通过装载货物的囊泡分泌到细胞外空间。囊泡运输的最后一步是运输囊泡与靶膜融合。SNARE蛋白对于所有囊泡融合步骤都是必不可少的，因此它们可能构成了一种保守的膜融合机制。根据“拉链”模型，它们组装成稳定的膜桥复合物，逐渐使膜并列。因此，复合物的形成可能提供克服两个膜之间排斥力所需的能量。在过去几年中，详细的结构和功能研究进一步证明SNAREs大多符合拉链模型。然而，尚不清楚膜之间的SNARE组装是否直接导致脂质双层的融合。
