Department of Pharmacy, College of Pharmacy, Cell Dynamics Research Center, Seoul National University, Seoul 151-742, Republic of Korea.
Cancer Lett. 2012 Jan 28;314(2):198-205. doi: 10.1016/j.canlet.2011.09.030. Epub 2011 Oct 19.
Transmembrane 4L six family member 5 (TM4SF5) can regulate cell-cell adhesion and cellular morphology via cytoplasmic p27(Kip1)-mediated changes in RhoA activity. However, how TM4SF5 causes cytosolic p27(Kip1) stabilization remains unknown. In this study we found that TM4SF5-mediated Ser10 phosphorylation of p27(Kip1) required for cytosolic localization was not always correlated with Akt activity. Inhibition or suppression of c-Jun N-terminal kinase (JNK) in TM4SF5-expressing cells decreased Ser10 phosphorylation of p27(Kip1) and rescued expression levels and localization of adherence junction molecules to cell-cell contacts. These observations suggest involvement of JNKs in TM4SF5-mediated p27(Kip1) Ser10 phosphorylation and localization during epithelial-mesenchymal transition.
跨膜 4L 六家族成员 5（TM4SF5）可以通过细胞质 p27（Kip1）介导的 RhoA 活性变化来调节细胞-细胞黏附作用和细胞形态。然而，TM4SF5 如何导致细胞质 p27（Kip1）的稳定仍然未知。在这项研究中，我们发现 TM4SF5 介导的 p27（Kip1）的 Ser10 磷酸化对于细胞质定位所必需的，但并不总是与 Akt 活性相关。在 TM4SF5 表达细胞中抑制或抑制 c-Jun N-末端激酶（JNK）会降低 p27（Kip1）的 Ser10 磷酸化，并挽救黏附连接分子在细胞-细胞接触处的表达水平和定位。这些观察结果表明 JNK 参与了 TM4SF5 介导的上皮-间充质转化过程中的 p27（Kip1）Ser10 磷酸化和定位。
