Involvement of nectin in the localization of junctional adhesion molecule at tight junctions
Involvement of nectin in the localization of junctional adhesion molecule at tight junctions
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DOI：
10.1038/sj.onc.1205875
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发表时间：
2002-10-31
期刊：
影响因子：
8
通讯作者：
Takai, Y
中科院分区：
文献类型：
--
作者：
Fukuhara, A;Irie, K;Takai, Y
连接粘附分子 (JAM) 是一种不依赖 Ca2+ 的免疫球蛋白样细胞间粘附分子，位于紧密连接 (TJ) 处。 Claudin 是一种关键的细胞间粘附分子，可在 TJ 处形成 TJ 链。 JAM 通过其细胞质尾部结合蛋白 ZO-1 与紧密蛋白结合。 JAM 还与 Par-3 相关，Par-3 是一种细胞极性蛋白，与 Par-6 和非典型蛋白激酶 C 形成三元复合物。Nectin 是另一种不依赖于 Ca2+ 的免疫球蛋白样细胞粘附分子，位于粘附连接 (AJ) 处。 Nectin 通过各自的细胞质尾结合蛋白 afadin 和连环蛋白与 E-cadherin 结合，并与 E-cadherin 协同参与 AJ 的形成。我们在此表明，nectin 还参与了 TJ 中 JAM 的本地化。在 Madin-Darby 犬肾 (MDCK) 细胞中形成由 AJ 和 Us 组成的连接复合物期间，JAM 被招募到基于 nectin 的细胞间粘附位点。 JAM 的这种募集受到 nectin 抑制剂的抑制，从而抑制了 nectin 的反式相互作用。涂有 nectin 细胞外片段的微珠与细胞 nectin 相互作用，也将 JAM 募集到珠子-MDCK 细胞接触位点。此外，当稳定表达外源JAM和Nectin的钙粘蛋白缺陷L成纤维细胞（Nectin-JAM-L细胞）与仅表达Nectin的L成纤维细胞（Nectin-L细胞）共培养时，JAM集中在Nectin-JAM-L和Nectin-L细胞之间的细胞-细胞粘附位点，而没有JAM的反式相互作用。 JAM 的定位和免疫沉淀分析表明，它通过 afadin 和 ZO-1 与 nectin 相关。这些结果表明，在上皮细胞中连接复合物的形成过程中，Nectin 在 JAM 在 Us 的定位中发挥作用。
Junctional adhesion molecule (JAM) is a Ca2+-independent immunoglobulin-like cell-cell adhesion molecule which localizes at tight junctions (TJs). Claudin is a key cell-cell adhesion molecule that forms TJ strands at TJs. JAM is associated with claudin through their cytoplasmic tail-binding protein, ZO-1. JAM is furthermore associated with Par-3, a cell polarity protein which forms a ternary complex with Par-6 and atypical protein kinase C. Nectin is another Ca2+-independent immunoglobulin-like cell-cell adhesion molecule which localizes at adherens junctions (AJs). Nectin is associated with E-cadherin through their respective cytoplasmic tail-binding proteins, afadin and catenins, and involved in the formation of AJs cooperatively with E-cadherin. We show here that nectin is furthermore involved in the localization of JAM at TJs. During the formation of the junctional complex consisting of AJs and Us in Madin-Darby canine kidney (MDCK) cells, JAM was recruited to the nectin-based cell-cell adhesion sites. This recruitment of JAM was inhibited by nectin inhibitors, which inhibited the trans-interaction of nectin. Microbeads coated with the extracellular fragment of nectin, that interacted with cellular nectin, also recruited JAM to the bead-MDCK cell contact sites. Furthermore, when cadherin-deficient L fibroblasts stably expressing both exogenous JAM and nectin (nectin-JAM-L cells) were co-cultured with L fibroblasts expressing only nectin (nectin-L cells), JAM was concentrated at the cell-cell adhesion sites between nectin-JAM-L and nectin-L cells without the trans-interaction of JAM. Analyses of the localization and immunoprecipitation of JAM revealed that it was associated with nectin through afadin and ZO-1. These results suggest that nectin has a role in the localization of JAM at Us in the process of the formation of the junctional complex in epithelial cells.