MRC-Laboratory, Molecular Cell Biology, and Department of Cell and Developmental Biology, UCL, Gower street, London, WC1E 6BT, UK.
Nat Cell Biol. 2010 Jul;12(7):628-32. doi: 10.1038/ncb0710-628.
Directed cell migration requires the breaking of cell symmetry to generate a cell front and a cell rear along an axis approximately aligned with the direction of locomotion. In most cell types, regulated actin polymerization promotes initial cell front formation and its subsequent persistent protrusion, whereas myosin II-based forces are required to initially create and then maintain the cell rear. Molecular models for cell migration have focused extensively on cell protrusion, and the breaking of cell symmetry is almost universally portrayed with the cell front forming first. Although data supports this model for cells moving towards chemo-attractants, in the absence of any guidance cue, cell symmetry is broken by the cells constitutively forming the cell rear first. This allows an alternative model for triggering cell migration starting with retraction at the back of the cell. In this model, actomyosin II activity within the cell body and prospective cell rear occurs before a spatial bias in actin polymerization at the cell front. Creating the cell rear first may be a useful tool employed by a wide-range of migrating cell types, particularly when moving away from repellent cues.
定向细胞迁移需要打破细胞对称性，沿大致与运动方向一致的轴线上生成一个细胞前缘和一个细胞后缘。在大多数细胞类型中，受调控的肌动蛋白聚合促进初始细胞前缘的形成及其随后的持续突出，而肌球蛋白 II 基力则需要最初形成并维持细胞后缘。细胞迁移的分子模型已经广泛关注细胞突出，并且细胞对称性的打破几乎普遍被描绘为先形成细胞前缘。尽管有数据支持这种朝向化学趋化物运动的细胞模型，但在没有任何导向信号的情况下，细胞通过持续地首先形成细胞后缘来打破对称性。这为从细胞后端的回缩开始触发细胞迁移提供了另一种模型。在这个模型中，细胞体和潜在的细胞后缘中的肌动球蛋白 II 活性发生在细胞前缘的肌动蛋白聚合的空间偏置之前。首先形成细胞后缘可能是广泛迁移细胞类型采用的一种有用工具，特别是在远离排斥信号时。
