SHIP2 interaction with the cytoskeletal protein Vinexin
SHIP2 interaction with the cytoskeletal protein Vinexin
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DOI：
10.1111/j.1742-4658.2005.04996.x
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发表时间：
2005-12-01
期刊：
影响因子：
5.4
通讯作者：
Erneux, C
中科院分区：
文献类型：
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作者：
Paternotte, N;Zhang, J;Erneux, C
含有 src 同源 2 (SH2) 结构域的肌醇 5-磷酸酶 2 (SHIP2) 催化磷脂酰肌醇 3,4,5-三磷酸 [PtdIns(3,4,5) P-3] 去磷酸化为磷脂酰肌醇 3,4-二磷酸 [PtdIns(3,4) P-2]。我们报告了细胞骨架蛋白 Vinexin 的鉴定，它是一种与 SHIP2 相互作用的蛋白质。这是通过使用 SHIP2 C 末端区域作为诱饵进行酵母双杂交筛选来实现的。 Vinexin 此前已被鉴定为纽蛋白结合蛋白，在细胞扩散和细胞骨架组织中发挥关键作用。 SHIP2 和 Vinexin 之间的相互作用在 COS-7 细胞和小鼠胚胎成纤维细胞 (MEF) 的裂解物中得到证实。 C 末端参与了相互作用，如 SHIP2 截短的 C 末端突变体的转染所示。此外，我们还显示了 Vinexin a 和 SHIP2 在转染的 COS-7 细胞周围的共定位。当体外添加至 SHIP2 时，Vinexin 不影响 SHIP2 的 PtdIns(3,4,5) P-3 5-磷酸酶活性。将 SHIP2 或 Vinexin 转染 COS-7 细胞后，细胞对胶原蛋白 I 包被的培养皿的粘附增强。无论是 SHIP2 的催化突变体还是 C 末端突变体，都不再观察到这种效应。它也似乎是 SHIP2 特有的； SHIP1 中未曾出现过这种情况。与MEF+/+细胞相比，SHIP2(-/-) MEF细胞对相同基质的粘附降低。我们的数据表明，SHIP2 与 Vinexin 的相互作用促进了 SHIP2 在细胞周围的定位，使其催化位点保持完整。 Vinexin 和 SHIP2 之间形成的复合物可能会增加细胞粘附。这些数据强化了这样的概念：SHIP2 作为 PtdIns(3,4,5) P-3 5-磷酸酶和焦点接触形成调节剂均具有活性。
The src homology 2 (SH2) domain-containing inositol 5-phosphatase 2 (SHIP2) catalyses the dephosphorylation of phosphatidylinositol 3,4,5-tris-phosphate [ PtdIns( 3,4,5) P-3] to phosphatidylinositol 3,4-bisphosphate [ PtdIns( 3,4) P-2]. We report the identification of the cytoskeletal protein Vinexin as a protein interacting with SHIP2. This was achieved by yeast two-hybrid screening using the C-terminal region of SHIP2 as bait. Vinexin has previously been identified as a vinculin-binding protein that plays a key role in cell spreading and cytoskeletal organization. The interaction between SHIP2 and Vinexin was confirmed in lysates of both COS-7 cells and mouse embryonic fibroblasts ( MEF). The C-terminus was involved in the interaction, as shown by the transfection of a truncated C-terminus mutant of SHIP2. In addition, we showed the colocalization between Vinexin a and SHIP2 at the periphery of transfected COS-7 cells. When added in vitro to SHIP2, Vinexin did not affect the PtdIns(3,4,5) P-3 5-phosphatase activity of SHIP2. Enhanced cell adhesion to collagen-I-coated dishes was shown upon transfection of either SHIP2 or Vinexin to COS-7 cells. This effect was no longer observed with either a catalytic mutant or the C-terminus mutant of SHIP2. It also appears SHIP2 specific; this was not seen with SHIP1. Adhesion to the same matrix was decreased in SHIP2(-/-) MEF cells compared with MEF+/+ cells. Our data suggest that SHIP2 interaction with Vinexin promotes the localization of SHIP2 at the periphery of the cells leaving its catalytic site intact. The complex formation between Vinexin and SHIP2 may increase cellular adhesion. The data reinforce the concept that SHIP2 is active both as a PtdIns(3,4,5) P-3 5-phosphatase and as a modulator of focal contact formation.