Clathrin dependent endocytosis of E-cadherin is regulated by the Arf6GAP isoform SMAP1
Clathrin dependent endocytosis of E-cadherin is regulated by the Arf6GAP isoform SMAP1
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DOI：
10.1016/j.yexcr.2007.11.006
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发表时间：
2008-04-15
影响因子：
3.7
通讯作者：
Satake, Masanobu
中科院分区：
文献类型：
--
作者：
Kon, Shunsuke;Tanabe, Kenji;Satake, Masanobu
e -钙粘蛋白是上皮细胞粘附连接的核心成分，并根据细胞类型通过网格蛋白包被的囊泡和/或小泡不断地进行内吞作用。在这项研究中，我们研究了SMAP1在e-钙粘蛋白内吞作用中的作用，SMAP1是一种网格蛋白相互作用的adp -核糖化因子6 (Arf6) GTPase的gtase激活蛋白（GAP）。以马汀-达比犬肾（MDCK）上皮细胞为模型，SMAP1定位于细胞质和e -钙粘蛋白存在的粘附连接处。接下来，将SMAP1的活性与其他Arf6GAPs（和/或Arf6-GTP的效应物），即GIT1和AMAP2/DDEF2的活性进行比较。SMAP1的过表达，而GIT1和AMAP2/DDEF2的过表达，强烈地抑制了E-cadherin的基础内化，以及磷酯诱导的内化。值得注意的是，AMAP2/DDEF2反而增强了小泡介导的膜蛋白的结合，而不是e-钙粘蛋白。因此，在MDCK细胞中，e -钙粘蛋白似乎仅通过smap1调节的网格蛋白包被囊泡被内吞。此外，通过伤口愈合和Transwell实验评估，与未转染的细胞相比，过表达SMAP1的MDCK细胞显示出细胞迁移程度的降低，迁移的减少似乎是由于过表达SMAP1的细胞在粘附连接处积聚了e -钙粘蛋白。总的来说，SMAP1可能代表了MDCK细胞中E-cadherin依赖网格蛋白内吞的关键Arf6GAP。SMAP1在e -钙粘蛋白转换中的活性可能参与上皮组织和/或上皮-间质转化。(C) 2007爱思唯尔公司版权所有。
E-cadherin is a central component of the adherens junction in epithelial cells and continuously undergoes endocytosis via clathrin-coated vesicles and/or caveolae depending on the cell type. In this study, we examined the role of SMAP1, a clathrin-interacting GTPase-activating protein (GAP) for the ADP-ribosylation factor 6 (Arf6) GTPase, in E-cadherin endocytosis. Mardin-Darby canine kidney (MDCK) epithelial cells were used as a model, and SMAP1 localized in the cytoplasm and along the adherens junction where E-cadherin was present. Next, activity of SMAP1 was compared with that of other Arf6GAPs (and/or an effector of Arf6-GTP), namely GIT1 and AMAP2/DDEF2. Overexpression of SMAP1 but not GIT1 nor AMAP2/DDEF2 strongly inhibited basal, as well as phorbolester-induced, internalization of E-cadherin. Notably, AMAP2/DDEF2 rather enhanced the caveolae-mediated incorporation of a membrane protein other than E-cadherin. Thus, in MDCK cells, E-cadherin appeared to be endocytosed solely through SMAP1-regulated clathrin-coated vesicles. Furthermore, MDCK cells overexpressing SMAP1 showed a reduced degree of cell migration compared to untransfected cells, as assessed by wound healing and Transwell assays, and this reduction in migration appeared to be due to the accumulation of E-cadherin at the adherens junction in cells overexpressing SMAP1. Collectively, SMAP1 likely represents a key Arf6GAP in clathrin dependent endocytosis of E-cadherin in MDCK cells. This activity of SMAP1 in E-cadherin turnover may be involved in epithelial organization and/or epithelial-mesenchymal transition. (C) 2007 Elsevier Inc. All rights reserved.