Nudel and FAK as antagonizing strength modulators of nascent adhesions through paxillin.
Nudel and FAK as antagonizing strength modulators of nascent adhesions through paxillin.
复制标题
Nudel 和 FAK 作为通过桩蛋白拮抗新生粘连的强度调节剂
DOI：
10.1371/journal.pbio.1000116
复制
发表时间：
2009-05-12
期刊：
影响因子：
9.8
通讯作者：
Zhu X
中科院分区：
文献类型：
--
作者：
Shan Y;Yu L;Li Y;Pan Y;Zhang Q;Wang F;Chen J;Zhu X
通过蛋白质Nudel和粘着斑激酶竞争结合细胞蛋白桩蛋白对于细胞粘附和迁移的适当调节是重要的。粘附和脱离是细胞迁移过程中协调的关键步骤。从概念上讲，有效的迁移既需要通过新生粘连在前缘处有效稳定膜突起，也需要通过破坏局灶性粘连在后侧回缩期间成功保持膜突起。由于新生粘连的尺寸比局灶性粘连小得多，因此预期它们表现出更强的粘附性，以实现细胞前后之间的协调。在这里，我们表明，Nudel敲低干扰RNA（RNAi）导致细胞边缘收缩，由于膜突起的粘附性差。Nudel绑定到桩蛋白，支架蛋白的焦点接触，并与它共定位在活跃的膜突起的地区，大概是在新生的粘连。粘着斑激酶（FAK）以桩蛋白结合依赖的方式破坏裸蛋白-桩蛋白相互作用。强制本地化的Nudel在所有的焦点接触融合桩蛋白显着加强其粘附性，而结构活化FAK或任何桩蛋白结合FAK突变体缺乏N-末端自抑制结构域的过表达引起细胞边缘收缩。这些结果表明，通过Nudel和FAK与桩蛋白的相互作用选择性增强新生粘附以促进细胞迁移的新机制。细胞迁移是单细胞和多细胞生物体的一个重要过程。在高等动物中，细胞迁移对于许多生物过程都很重要，包括胚胎发育，免疫反应和伤口愈合。癌细胞侵入健康组织是不适当的细胞迁移的结果。当在实验室中培养时可以容易地观察到，哺乳动物细胞通过粘着斑附着到表面，细胞结构的特征在于跨膜蛋白整联蛋白和细胞内蛋白质（包括桩蛋白和粘着斑激酶（FAK））的复合物。为了使细胞移动，它们必须协调两个过程：细胞前缘的延伸和后缘的收缩。为了实现这一点，细胞首先从前缘突出膜结构，然后建立称为新生粘附的粘附结构，以将延伸部分保持在适当位置。与此同时，将细胞固定在适当位置的粘着斑必须被破坏，以使细胞的后边缘缩回。在这里，我们发现一种名为Nudel的蛋白质在移动细胞的前缘富集，在那里它与桩蛋白相互作用，但在粘着斑中未检测到。我们进一步表明，粘着斑蛋白FAK是能够取消裸桩蛋白的相互作用，导致抑制新生粘连的形成和细胞延伸的损失。因此，我们提出了一个模型，在新生的粘连和焦点粘连中的桩蛋白相互作用的调制是协调细胞运动的关键：裸桩蛋白相互作用增强新生的粘连的强度，以促进膜突起在细胞的前边缘的附着，而FAK防止裸桩蛋白相互作用焦点粘连，以促进细胞的后边缘的回缩。
Competition for binding to the cellular protein paxillin by the proteins Nudel and focal adhesion kinase is important for the proper regulation of cell adhesion and migration. Adhesion and detachment are coordinated critical steps during cell migration. Conceptually, efficient migration requires both effective stabilization of membrane protrusions at the leading edge via nascent adhesions and their successful persistence during retraction of the trailing side via disruption of focal adhesions. As nascent adhesions are much smaller in size than focal adhesions, they are expected to exhibit a stronger adhesivity in order to achieve the coordination between cell front and back. Here, we show that Nudel knockdown by interference RNA (RNAi) resulted in cell edge shrinkage due to poor adhesions of membrane protrusions. Nudel bound to paxillin, a scaffold protein of focal contacts, and colocalized with it in areas of active membrane protrusions, presumably at nascent adhesions. The Nudel-paxillin interaction was disrupted by focal adhesion kinase (FAK) in a paxillin-binding–dependent manner. Forced localization of Nudel in all focal contacts by fusing it to paxillin markedly strengthened their adhesivity, whereas overexpression of structurally activated FAK or any paxillin-binding FAK mutant lacking the N-terminal autoinhibitory domain caused cell edge shrinkage. These results suggest a novel mechanism for selective reinforcement of nascent adhesions via interplays of Nudel and FAK with paxillin to facilitate cell migration. Cell migration is an essential process in both single-cell and multicellular organisms. In higher animals, cell migration is important for many biological processes, including embryonic development, the immune response, and wound healing. Cancer cell invasion into healthy tissues occurs as a result of inappropriate cell migration. As can be easily visualized when cultured in the lab, mammalian cells attach to surfaces through focal adhesions, cellular structures characterized by complexes of the transmembrane protein integrin and intracellular proteins including paxillin and focal adhesion kinase (FAK). In order for cells to move, they must coordinate two processes: extension of the front edge of the cell and retraction of the back edge. To accomplish this, a cell first protrudes membranous structures from the front edge and then establishes adhesion structures known as nascent adhesions to hold the extensions in place. At the same time, the focal adhesions that hold a cell in place must be disrupted in order for the back edge of the cell to retract. Here, we show that a protein called Nudel is enriched at the front edge of moving cells, where it interacts with paxillin but is not detected in focal adhesions. We further show that the focal adhesion protein FAK is able to abolish the Nudel-paxillin interaction, leading to repression of the formation of nascent adhesions and to the loss of cell extensions. We therefore propose a model in which modulation of paxillin interactions in nascent adhesions and in focal adhesions is critical for coordinated cell movement: the Nudel-paxillin interaction enhances the strength of nascent adhesions to promote the attachment of membrane protrusions at the front edge of the cell, whereas FAK prevents the Nudel-paxillin interaction in focal adhesions in order to facilitate retraction of the back edge of the cell.
登录
查看更多内容
影响因子：
4.8
作者：
Huang, C;Liu, JL;Zhan, X
通讯作者：
Zhan, X
DOI：
10.1083/jcb.200204153
发表时间：
2002-11-25
期刊：
The Journal of cell biology
影响因子：
--
作者：
Galbraith CG;Yamada KM;Sheetz MP
通讯作者：
Sheetz MP
影响因子：
7.8
作者：
Dujardin, Denis L;Barnhart, Lora E;Stehman, Stephanie A;Gomes, Edgar R;Gundersen, Gregg G;Vallee, Richard B
通讯作者：
Vallee, Richard B
p38mapk对帕西林的磷酸化参与PC-12细胞的神经突延伸。
DOI：
10.1083/jcb.200307081
发表时间：
2004-02-16
期刊：
The Journal of cell biology
影响因子：
--
作者：
Huang C;Borchers CH;Schaller MD;Jacobson K
通讯作者：
Jacobson K
影响因子：
21.3
作者：
Balaban, NQ;Schwarz, US;Geiger, B
通讯作者：
Geiger, B