Actomyosin tension is required for correct recruitment of adherens junction components and zonula occludens formation
Actomyosin tension is required for correct recruitment of adherens junction components and zonula occludens formation
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DOI：
10.1016/j.yexcr.2006.01.031
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发表时间：
2006-05-15
影响因子：
3.7
通讯作者：
Yonemura, Shigenobu
中科院分区：
文献类型：
--
作者：
Miyake, Yuka;Inoue, Naoko;Yonemura, Shigenobu
与肌动蛋白丝紧密相连的粘附连接（AJ）是主要的细胞-细胞粘附结构。为了理解肌动蛋白丝在AJ形成中的重要性，我们首先分析了NRK成纤维细胞中的点状AJ，其中一个肌动蛋白索与一个AJ结构单元结合。AJ组分如钙粘蛋白/连环蛋白复合物和黏着斑蛋白的积累，以及AJ相关肌动蛋白电缆的形成依赖于Rho活性。Rho靶点的抑制剂ROCK（调节肌球蛋白II活性）和肌球蛋白II ATP酶的抑制剂阻止了AJ组分的积累，表明肌球蛋白II活性比Rho活性更直接参与。通过RNAi消耗肌球蛋白II显示出类似的结果。极化上皮MTD-1A细胞中肌球蛋白II活性的抑制影响黏着斑蛋白向周围AJ（粘附小带）的积累。此外，沿着顶基底轴的正确的闭合小带（紧密连接）的形成也受到损害，这需要钙粘蛋白的活性。虽然MDCK细胞，通常被用作典型的上皮细胞没有一个典型的小带粘附，点状AJs形成依赖于肌球蛋白II活性诱导伤口闭合的MDCK细胞片。这些发现表明，肌动球蛋白产生的张力是必要的正确AJ组装。(c)2006年爱思唯尔公司All rights reserved.
The adherens junction (AJ) densely associated with actin filaments is a major cell-cell adhesion structure. To understand the importance of actin filament association in AJ formation, we first analyzed punctate AJs in NRK fibroblasts where one actin cable binds to one AJ structure unit. The accumulation of AJ components such as the cadherin/catenin complex and vinculin, as well as the formation of AJ-associated actin cables depended on Rho activity. Inhibitors for the Rho target, ROCK, which regulates myosin II activity, and for myosin II ATPase prevented the accumulation of AJ components, indicating that myosin II activity is more directly involved than Rho activity. Depletion of myosin II by RNAi showed similar results. The inhibition of myosin II activity in polarized epithelial MTD-1A cells affected the accumulation of vinculin to circumferential AJ (zonula adherens). Furthermore, correct zonula occludens (tight junction) formation along the apicobasal axis that requires cadherin activity was also impaired. Although MDCK cells which are often used as typical epithelial cells do not have a typical zonula adherens, punctate AJs formed dependently on myosin II activity by inducing wound closure in a MDCK cell sheet. These findings suggest that tension generated by actomyosin is essential for correct AJ assembly. (c) 2006 Elsevier Inc. All rights reserved.