Interaction of activated Rab5 with actin-bundling proteins, L- and T-plastin and its relevance to endocytic functions in mammalian cells
Interaction of activated Rab5 with actin-bundling proteins, L- and T-plastin and its relevance to endocytic functions in mammalian cells
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DOI：
10.1016/j.bbrc.2011.03.082
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发表时间：
2011-04-15
影响因子：
3.1
通讯作者：
Yamamoto, Yuji
中科院分区：
文献类型：
--
作者：
Hagiwara, Makoto;Shinomiya, Hiroto;Yamamoto, Yuji
Rab5 是一种 GTP 结合蛋白，对于内吞机制功能至关重要。我们之前使用具有组成型活性 Rab5 的亲和柱将 L-plastin 鉴定为 Rab5 的结合蛋白。 L-和T-塑蛋白是属于肌动蛋白成束蛋白的塑蛋白家族的亚型，参与细胞形态、板状足突出、细菌侵袭和肿瘤进展的调节。然而，Rab5 与塑性蛋白结合的生理相关性仍不清楚。在这里，我们表明 L-和 T-plastin 仅与激活的 Rab5 相互作用，并且它们与 Rab5 共定位在质膜和内体上。在 L- 和 T-plastin 过表达 Cos-1 细胞中，Rab5 活性也较高。此外，L-和T-plastin的表达增加了液相内吞作用的速率。这些发现表明 Rab5 要么被激活，要么通过与塑蛋白的相互作用维持其活性，并且这种相互作用影响内吞活性。 (C) 2011 Elsevier Inc. 保留所有权利。
Rab5 is a GTP-binding protein that is crucial for endocytic machinery functions. We previously identified L-plastin as a binding protein for Rab5, using an affinity column with constitutively active Rab5. L- and T-plastin are isoforms of a plastin protein family belonging to actin-bundling proteins that are implicated in the regulation of cell morphology, lamellipodium protrusion, bacterial invasion and tumor progression. However, the physiological relevance of Rab5 binding to plastin has remained unclear. Here, we show that L- and T-plastin interacted only with activated Rab5 and that they co-localized with Rab5 on the plasma membrane and endosome. Rab5 activity was also higher in both L- and T-plastin over-expressing Cos-1 cells. Furthermore, expression of L- and T-plastin increased the rate of fluid-phase endocytosis. These findings imply that the Rab5 is either activated or the activity is sustained by interaction with plastin, and that this interaction influences endocytic activity. (C) 2011 Elsevier Inc. All rights reserved.