Shibata T, Gotoh M, Ochiai A, Hirohashi S
Pathology Division, National Cancer Center Research Institute, Tokyo, Japan.
Biochem Biophys Res Commun. 1994 Aug 30;203(1):519-22. doi: 10.1006/bbrc.1994.2213.
Plakoglobin is a cytoplasmic protein localized in both adherens junctions and desmosomes. Little is known about its function, but it may play a role in maintaining cell junction integrity. A partly homologous protein, beta catenin, is localized mainly in adherens junctions and plays a key role in cell adhesion by associating with cadherins, a family of Ca2+ dependent cell-to-cell adhesion molecules. Recently the product of APC, a tumor suppressor gene, was found to associate with beta catenin. In this study we demonstrated that plakoglobin also associates with APC and that tyrosine phosphorylated plakoglobin associates with cadherins but not with APC. These results suggest that plakoglobin could play a role in mediating the signals of APC by mutual interaction and that this may be regulated by tyrosine phosphorylation.
桥粒斑珠蛋白是一种定位于黏着连接和桥粒的胞质蛋白。对其功能了解甚少，但它可能在维持细胞连接完整性方面发挥作用。一种部分同源的蛋白，β-连环蛋白，主要定位于黏着连接，并通过与钙黏蛋白（一类依赖Ca2+的细胞间黏附分子家族）结合在细胞黏附中起关键作用。最近发现肿瘤抑制基因APC的产物与β-连环蛋白相关。在本研究中，我们证明桥粒斑珠蛋白也与APC相关，并且酪氨酸磷酸化的桥粒斑珠蛋白与钙黏蛋白结合，但不与APC结合。这些结果表明，桥粒斑珠蛋白可能通过相互作用在介导APC的信号中发挥作用，并且这可能受酪氨酸磷酸化调节。
