Cleghorn Whitney M, Branch Kevin M, Kook Seunghyi, Arnette Christopher, Bulus Nada, Zent Roy, Kaverina Irina, Gurevich Eugenia V, Weaver Alissa M, Gurevich Vsevolod V
Department of Pharmacology, Vanderbilt University, Nashville, TN 37232.
Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232.
Mol Biol Cell. 2015 Feb 15;26(4):622-35. doi: 10.1091/mbc.E14-02-0740. Epub 2014 Dec 24.
Focal adhesions (FAs) play a key role in cell attachment, and their timely disassembly is required for cell motility. Both microtubule-dependent targeting and recruitment of clathrin are critical for FA disassembly. Here we identify nonvisual arrestins as molecular links between microtubules and clathrin. Cells lacking both nonvisual arrestins showed excessive spreading on fibronectin and poly-d-lysine, increased adhesion, and reduced motility. The absence of arrestins greatly increases the size and lifespan of FAs, indicating that arrestins are necessary for rapid FA turnover. In nocodazole washout assays, FAs in arrestin-deficient cells were unresponsive to disassociation or regrowth of microtubules, suggesting that arrestins are necessary for microtubule targeting-dependent FA disassembly. Clathrin exhibited decreased dynamics near FA in arrestin-deficient cells. In contrast to wild-type arrestins, mutants deficient in clathrin binding did not rescue the phenotype. Collectively the data indicate that arrestins are key regulators of FA disassembly linking microtubules and clathrin.
粘着斑（FAs）在细胞附着过程中起关键作用，细胞运动需要粘着斑及时解聚。网格蛋白的微管依赖性靶向和募集对于粘着斑的解聚都至关重要。在此，我们鉴定出非视觉抑制蛋白是微管与网格蛋白之间的分子连接物。缺乏两种非视觉抑制蛋白的细胞在纤连蛋白和聚 -d-赖氨酸上过度铺展，粘附增加且运动性降低。抑制蛋白的缺失极大地增加了粘着斑的大小和寿命，表明抑制蛋白对于粘着斑的快速更新是必需的。在诺考达唑洗脱实验中，抑制蛋白缺陷细胞中的粘着斑对微管的解聚或再生无反应，这表明抑制蛋白对于微管靶向依赖性粘着斑解聚是必需的。在抑制蛋白缺陷细胞中，网格蛋白在粘着斑附近的动力学表现降低。与野生型抑制蛋白相反，缺乏网格蛋白结合能力的突变体无法挽救该表型。总体而言，这些数据表明抑制蛋白是连接微管和网格蛋白的粘着斑解聚的关键调节因子。
