Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
J Proteomics. 2012 Jul 16;75(13):3952-62. doi: 10.1016/j.jprot.2012.05.017. Epub 2012 May 29.
Porosomes are the universal secretory portals at the cell plasma membrane, where membrane-bound secretory vesicles transiently dock and fuse to expel intravesicular contents to the outside during cell secretion. In the past decade, the neuronal porosome complex, a 10-15nm cup-shaped lipoprotein structure has been isolated, its partial composition and 3D contour map determined, and it has been functionally reconstituted into artificial lipid membrane. Here we further determine the composition of the neuronal porosome proteome using immunoisolation and gel filtration chromatography, followed by tandem mass spectrometry. Results from the study demonstrate nearly 40 proteins to constitute the neuronal porosome proteome. Furthermore, interaction of proteins within the porosome and their resulting arrangement is predicted. The association and dissociation of proteins at the porosome following stimulation of cell secretion demonstrate the dynamic nature of the organelle.
质膜有核小体，是普遍存在的分泌门户，在此处，膜结合的分泌小泡短暂停靠并融合，将小泡内物质排出细胞外。在过去十年中，神经元核小体复合物，一种 10-15nm 的杯状脂蛋白结构已被分离出来，其部分组成和 3D 轮廓图已被确定，并被功能重建到人工脂质膜中。在这里，我们使用免疫分离和凝胶过滤层析，然后进行串联质谱法，进一步确定神经元核小体蛋白组的组成。研究结果表明，有近 40 种蛋白质构成了神经元核小体蛋白组。此外，还预测了核小体内部蛋白质的相互作用及其排列方式。细胞分泌刺激后，核小体上蛋白质的结合和解离，显示出该细胞器的动态性质。
