Disruption of the talin gene compromises focal adhesion assembly in undifferentiated but not differentiated embryonic stem cells.
Disruption of the talin gene compromises focal adhesion assembly in undifferentiated but not differentiated embryonic stem cells.
复制标题
塔林基因的破坏会损害未分化但没有分化的胚胎干细胞中的局灶性组件。
DOI：
10.1083/jcb.142.4.1121
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发表时间：
1998-08-24
影响因子：
7.8
通讯作者：
Critchley, D R
中科院分区：
文献类型：
--
作者：
Priddle, H;Hemmings, L;Monkley, S;Woods, A;Patel, B;Sutton, D;Dunn, G A;Zicha, D;Critchley, D R
我们利用基因破坏技术分离出了两个不含完整踝蛋白的踝蛋白（−/−）胚胎干细胞突变体。未分化的细胞（a）无法在明胶或层粘连蛋白上扩散，而是呈圆形集落生长，尽管它们能够在纤连蛋白上扩散；（b）对层粘连蛋白的黏附性降低，但对纤连蛋白的黏附性未降低；（c）β1整合素的表达水平大幅降低，尽管α5和αV的水平为野生型；（d）与黏着斑蛋白（−/−）胚胎干细胞突变体相比，其极化程度较低，膜突起增多；（e）在纤连蛋白上无法组装含黏着斑蛋白或桩蛋白的黏着斑以及肌动蛋白应力纤维，而黏着斑蛋白（−/−）胚胎干细胞能够组装含踝蛋白的黏着斑。两个踝蛋白（−/−）胚胎干细胞突变体都形成了拟胚体，但分化仅限于两种形态不同的细胞类型。有趣的是，这些分化的踝蛋白（−/−）胚胎干细胞能够在纤连蛋白上扩散并形成含黏着斑蛋白和桩蛋白的类似黏着斑的结构。此外，β1整合素亚基的水平与野生型胚胎干细胞中的水平相当。我们得出结论，踝蛋白对于未分化胚胎干细胞中β1整合素的表达以及黏着斑的组装至关重要，但一部分分化细胞在这两种特性上不依赖于踝蛋白。
We have used gene disruption to isolate two talin (−/−) ES cell mutants that contain no intact talin. The undifferentiated cells (a) were unable to spread on gelatin or laminin and grew as rounded colonies, although they were able to spread on fibronectin (b) showed reduced adhesion to laminin, but not fibronectin (c) expressed much reduced levels of β1 integrin, although levels of α5 and αV were wild-type (d) were less polarized with increased membrane protrusions compared with a vinculin (−/−) ES cell mutant (e) were unable to assemble vinculin or paxillin-containing focal adhesions or actin stress fibers on fibronectin, whereas vinculin (−/−) ES cells were able to assemble talin-containing focal adhesions. Both talin (−/−) ES cell mutants formed embryoid bodies, but differentiation was restricted to two morphologically distinct cell types. Interestingly, these differentiated talin (−/−) ES cells were able to spread and form focal adhesion-like structures containing vinculin and paxillin on fibronectin. Moreover, the levels of the β1 integrin subunit were comparable to those in wild-type ES cells. We conclude that talin is essential for β1 integrin expression and focal adhesion assembly in undifferentiated ES cells, but that a subset of differentiated cells are talin independent for both characteristics.