Awan Abida, Lucic Melinda R, Shaw David M, Sheppard Freda, Westwater Caroline, Lyons Steve A, Stern Peter L
CRC Immunology Group, CRC Molecular Biology Group, The Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Wilmslow Road, Manchester, M20 4BX, United Kingdom.
Biochem Biophys Res Commun. 2002 Jan 25;290(3):1030-6. doi: 10.1006/bbrc.2001.6288.
Overexpression of the 5T4 transmembrane glycoprotein can have marked effects on both the actin cytoskeleton and cell migration. Using a yeast two-hybrid approach, we describe a novel interaction between 5T4 and TIP-2/GIPC, a cytoplasmic interacting protein containing a PDZ domain. The cytoplasmic tail of 5T4 contains a class I PDZ-binding motif (Ser-Asp-Val) and we demonstrate that this region, in particular the terminal valine, is required for 5T4 interaction with TIP-2/GIPC. HeLa cells expressing hemagglutinin-tagged TIP-2/GIPC (HA-TIP-2/GIPC) have an altered distribution of endogenous 5T4, which colocalizes with HA-TIP-2/GIPC, thus supporting an interaction. Furthermore, TIP-2/GIPC can be coimmunoprecipitated with 5T4 from HeLa cell lysates. Identification of the 5T4 and TIP-2/GIPC interaction provides the first link between 5T4 and the actin cytoskeleton. Since other proteins, like 5T4, associate with TIP-2/GIPC and are linked with cancer, we explore the possibility that TIP-2/GIPC may be a common factor involved in the cancer process.
5T4跨膜糖蛋白的过表达可对肌动蛋白细胞骨架和细胞迁移产生显著影响。利用酵母双杂交方法，我们描述了5T4与TIP-2/GIPC之间的一种新型相互作用，TIP-2/GIPC是一种含有PDZ结构域的细胞质相互作用蛋白。5T4的细胞质尾巴包含一个I类PDZ结合基序（Ser-Asp-Val），我们证明该区域，特别是末端缬氨酸，是5T4与TIP-2/GIPC相互作用所必需的。表达血凝素标记的TIP-2/GIPC（HA-TIP-2/GIPC）的HeLa细胞内源性5T4的分布发生改变，其与HA-TIP-2/GIPC共定位，从而支持了这种相互作用。此外，TIP-2/GIPC可与HeLa细胞裂解物中的5T4进行共免疫沉淀。5T4与TIP-2/GIPC相互作用的鉴定提供了5T4与肌动蛋白细胞骨架之间的首个联系。由于其他蛋白质，如5T4，与TIP-2/GIPC相关联并与癌症有关，我们探讨了TIP-2/GIPC可能是参与癌症过程的一个共同因素的可能性。
