Fractionation of the epithelial apical junctional complex: Reassessment of protein distributions in different substructures
Fractionation of the epithelial apical junctional complex: Reassessment of protein distributions in different substructures
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DOI：
10.1091/mbc.e04-09-0827
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发表时间：
2005-02-01
影响因子：
3.3
通讯作者：
Nelson, WJ
中科院分区：
文献类型：
--
作者：
Vogelmann, R;Nelson, WJ
上皮顶端连接复合体（epithelial apical junctional complex，AJC）是细胞结构和功能的重要调节因子。AJC被划分为包括紧密连接和粘附连接的亚结构，以及含有膜蛋白连接素、连接粘附分子和碎屑的其他膜复合物。此外，许多外周膜蛋白定位于AJC。分离的蛋白质的研究表明，潜在的结合伙伴，其中有广泛的重叠，在不同的AJC亚结构的蛋白质之间的相互作用的复杂的地图。作为一种替代直接搜索特定的蛋白质-蛋白质相互作用，我们试图分离膜亚结构的AJC在碘克沙醇密度梯度和定义其蛋白质成分。结果表明，AJC可以断裂成含有特定膜和外周膜蛋白的膜亚结构。每个子结构的组成揭示了一个更有限的重叠，在共同的蛋白质比从潜在的相互作用的库存预测，一些重叠的蛋白质可能参与逐步招聘和组装的AJC子结构。
The epithelial apical junctional complex (AJC) is an important regulator of cell structure and function. The AJC is compartmentalized into substructures comprising the tight and adherens junctions, and other membrane complexes containing the membrane proteins nectin, junctional adhesion molecule, and crumbs. In addition, many peripheral membrane proteins localize to the AJC. Studies of isolated proteins indicate a complex map of potential binding partners in which there is extensive overlap in the interactions between proteins in different AJC substructures. As an alternative to a direct search for specific protein-protein interactions, we sought to separate membrane substructures of the AJC in iodixanol density gradients and define their protein constituents. Results show that the AJC can be fractured into membrane substructures that contain specific membrane and peripheral membrane proteins. The composition of each substructure reveals a more limited overlap in common proteins than predicted from the inventory of potential interactions; some of the overlapping proteins may be involved in stepwise recruitment and assembly of AJC substructures.