Gupton Stephanie L, Waterman-Storer Clare M
Department of Cell Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Cell. 2006 Jun 30;125(7):1361-74. doi: 10.1016/j.cell.2006.05.029.
Cells exhibit a biphasic migration-velocity response to increasing adhesion strength, with fast migration occurring at intermediate extracellular matrix (ECM) concentration and slow migration occurring at low and high ECM concentration. A simple mechanical model has been proposed to explain this observation, in which too little adhesion does not provide sufficient traction whereas too much adhesion renders cells immobile. Here we characterize a phenotype for rapid cell migration, which in contrast to the previous model reveals a complex interdependence of subcellular systems that mediates optimal cell migration in response to increasing adhesion strength. The organization and activity of actin, myosin II, and focal adhesions (FAs) are spatially and temporally highly variable and do not exhibit a simple correlation with optimal motility rates. Furthermore, we can recapitulate rapid migration at a nonoptimal ECM concentration by manipulating myosin II activity. Thus, the interplay between actomyosin and FA dynamics results in a specific balance between adhesion and contraction, which induces maximal migration velocity.
细胞对增加的黏附强度呈现双相迁移速度反应,在细胞外基质(ECM)浓度适中时迁移速度快,而在ECM浓度低和高时迁移速度慢。提出了一个简单的力学模型来解释这一现象,其中黏附力过小无法提供足够的牵引力,而黏附力过大则使细胞无法移动。在这里,我们描述了一种快速细胞迁移的表型,与之前的模型不同,该表型揭示了亚细胞系统之间复杂的相互依赖关系,这种关系介导了细胞对增加的黏附强度做出的最佳迁移反应。肌动蛋白、肌球蛋白II和黏着斑(FAs)的组织和活性在空间和时间上高度可变,并且与最佳运动速率没有简单的相关性。此外,我们可以通过操纵肌球蛋白II的活性在非最佳ECM浓度下重现快速迁移。因此,肌动球蛋白和FA动力学之间的相互作用导致了黏附与收缩之间的特定平衡,从而诱导最大迁移速度。