Nuclear localization of the tight junction protein ZO-2 in epithelial cells
Nuclear localization of the tight junction protein ZO-2 in epithelial cells
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DOI：
10.1006/excr.2001.5457
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发表时间：
2002-03-10
影响因子：
3.7
通讯作者：
González-Mariscal, L
中科院分区：
文献类型：
--
作者：
Islas, S;Vega, J;González-Mariscal, L
紧密连接构成溶质和水流过上皮和内皮的细胞旁间隙的主要屏障。它由跨膜蛋白和膜下分子如MAGUKs ZO形成。我们以前已经发现，几个MAGUKs，包括紧密连接（ZO-1，ZO-2和ZO-3）和分隔连接（tamou和Dlg），包含一个或两个位于其第一个PDZ和GK结构域的核分选信号。现在，我们表明，这些蛋白质也包含核输出信号，并将我们的研究重点放在ZO-2的核膜穿梭。在稀疏培养物中，该分子聚集在细胞核中，在那里它与剪接因子SC 35部分共定位。随着单层细胞通过对核输出抑制剂链霉素B敏感的过程获得融合，核染色减少。核定位可以通过损害细胞-细胞接触、机械损伤来诱导。从细胞周边穿梭进入细胞核的ZO-2不是新合成的，而是来自于先前存在的库。这种蛋白质的运动是由肌动蛋白细胞骨架介导的。(C)2002 Elsevier Science（美国）。
The tight junction constitutes the major barrier to solute and water flow through the paracellular space of epithelia and endothelia. It is formed by transmembrane proteins and submembranous molecules such as the MAGUKs ZOs. We have previously found that several MAGUKs, including those of the tight (ZO-1, ZO-2, and ZO-3) and septate junction (tamou and Dlg), contain one or two nuclear sorting signals located at their first PDZ and GK domains. Now we show that these proteins also contain a nuclear export signal and focus our study on the nuclear membrane shuttling of ZO-2. In sparse cultures this molecule concentrates at the nucleus in clusters, where it partially colocalizes with splicing factor SC35. Nuclear staining diminishes as the monolayer acquires confluence through a process sensitive to the nuclear export inhibitor leptomycin B. Nuclear localization can be induced by impairing cell-cell contacts, by mechanical injury. ZO-2 that shuttles from the cell periphery into the nucleus is not newly synthesized but originates from a preexistent pool. The movement of this protein is mediated by the actin cytoskeleton. (C) 2002 Elsevier Science (USA).