ZO-1 and ZO-2 independently determine where claudins are polymerized in tight-junction strand formation
ZO-1 and ZO-2 independently determine where claudins are polymerized in tight-junction strand formation
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DOI：
10.1016/j.cell.2006.06.043
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发表时间：
2006-08-25
期刊：
影响因子：
64.5
通讯作者：
Tsukita, Shoichiro
中科院分区：
文献类型：
--
作者：
Umeda, Kazuaki;Ikenouchi, Junichi;Tsukita, Shoichiro
细胞和发育生物学中的一个基本问题是上皮细胞如何构建扩散屏障，使它们能够将不同的身体隔室分开。紧密连接（TJ）链的形成，这是至关重要的，这种屏障，涉及聚合的封闭蛋白，TJ粘附分子，在时间和空间的方式。ZO-1和ZO-2是主要的含PDZ结构域的TJ蛋白，并直接结合到claudin，但它们的功能作用知之甚少。我们建立了培养的上皮细胞（1（ko）/2（kd）），其中ZO-1/ZO-2的表达分别被同源重组和RNA干扰抑制。这些细胞极化良好，除了完全缺乏TJ。当在1（ko）/2（kd）细胞中外源表达时，ZO-1和ZO-2被募集到紧密连接蛋白聚合的交界区域，但仅含有结构域PDZ 1 -3的截短ZO-1（NZO-1）没有。当NZO-1被强制募集到侧膜并二聚化时，紧密连接蛋白显著聚合。这些发现表明，ZO-1和ZO-2可以独立地决定是否和在密封蛋白聚合。
A fundamental question in cell and developmental biology is how epithelial cells construct the diffusion barrier allowing them to separate different body compartments. Formation of tight junction (TJ) strands, which are crucial for this barrier, involves the polymerization of claudins, TJ adhesion molecules, in temporal and spatial manners. ZO-1 and ZO-2 are major PDZ-domain-containing TJ proteins and bind directly to claudins, yet their functional roles are poorly understood. We established cultured epithelial cells (1(ko)/2(kd)) in which the expression of ZO-1/ZO-2 was suppressed by homologous recombination and RNA interference, respectively. These cells were well polarized, except for a complete lack of TJs. When exogenously expressed in, l(ko)/2(kd) cells, ZO-1 and ZO-2 were recruited to junctional areas where claudins were polymerized, but truncated ZO-1 (NZO-1) containing only domains PDZ1-3 was not. When NZO-1 was forcibly recruited to lateral membranes and dimerized, claudins were dramatically polymerized. These findings indicate that ZO-1 and ZO-2 can independently determine whether and where claudins are polymerized.