Galbraith Catherine G, Yamada Kenneth M, Galbraith James A
National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA.
Science. 2007 Feb 16;315(5814):992-5. doi: 10.1126/science.1137904.
Migrating cells extend protrusions, probing the surrounding matrix in search of permissive sites to form adhesions. We found that actin fibers polymerizing along the leading edge directed local protrusions and drove synchronous sideways movement of beta1 integrin adhesion receptors. These movements lead to the clustering and positioning of conformationally activated, but unligated, beta1 integrins along the leading edge of fibroblast lamellae and growth cone filopodia. Thus, rapid actin-based movement of primed integrins along the leading edge suggests a "sticky fingers" mechanism to probe for new adhesion sites and to direct migration.
迁移细胞会伸出突起，探测周围基质以寻找形成黏附的许可位点。我们发现，沿前沿聚合的肌动蛋白纤维引导局部突起，并驱动β1整合素黏附受体同步侧向移动。这些移动导致构象激活但未结合配体的β1整合素在成纤维细胞片状伪足和生长锥丝状伪足的前沿聚集和定位。因此，引发的整合素沿前沿基于肌动蛋白的快速移动提示了一种“粘性手指”机制，用于探测新的黏附位点并指导迁移。
