Actomyosin pulls to advance the nucleus in a migrating tissue cell.
Actomyosin pulls to advance the nucleus in a migrating tissue cell.
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DOI：
10.1016/j.bpj.2013.11.4489
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发表时间：
2014-01
影响因子：
3.4
通讯作者：
Jun Wu;Ian A Kent;Nandini Shekhar;T. J. Chancellor;Agnes Mendonca;R. Dickinson;T. Lele
中科院分区：
文献类型：
--
作者：
Jun Wu;Ian A Kent;Nandini Shekhar;T. J. Chancellor;Agnes Mendonca;R. Dickinson;T. Lele
在迁移的组织细胞中，细胞骨架力参与细胞核的移位仍然没有解决。以前的研究已经不同程度地涉及肌动球蛋白产生的对细胞核的推力或拉力，以及细胞核结合微管马达的拉力。我们发现，在一个孤立的迁移细胞核可以向前移动，没有任何后缘脱离。当一个新的板状伪足被Rac 1的光激活所触发时，核向新的板状伪足移动。这种向前运动需要核-细胞骨架连接和肌球蛋白活性。顶端或基底肌动球蛋白束被发现不翻译与核。虽然微管抑制细胞核位置的波动，但在细胞迁移过程中细胞核的正向移位并不需要微管。后缘分离和用微针拉动产生核的运动和变形，这表明核和后缘之间存在机械耦合。值得注意的是，通过KASH过表达将细胞核与细胞骨架解耦，大大降低了后缘脱离的频率。总的来说，这些结果解释了细胞核如何在爬行的成纤维细胞中移动，并提高了力可以通过细胞核从细胞前部传递到后部的可能性。
The cytoskeletal forces involved in translocating the nucleus in a migrating tissue cell remain unresolved. Previous studies have variously implicated actomyosin-generated pushing or pulling forces on the nucleus, as well as pulling by nucleus-bound microtubule motors. We found that the nucleus in an isolated migrating cell can move forward without any trailing-edge detachment. When a new lamellipodium was triggered with photoactivation of Rac1, the nucleus moved toward the new lamellipodium. This forward motion required both nuclear-cytoskeletal linkages and myosin activity. Apical or basal actomyosin bundles were found not to translate with the nucleus. Although microtubules dampen fluctuations in nuclear position, they are not required for forward translocation of the nucleus during cell migration. Trailing-edge detachment and pulling with a microneedle produced motion and deformation of the nucleus suggestive of a mechanical coupling between the nucleus and the trailing edge. Significantly, decoupling the nucleus from the cytoskeleton with KASH overexpression greatly decreased the frequency of trailing-edge detachment. Collectively, these results explain how the nucleus is moved in a crawling fibroblast and raise the possibility that forces could be transmitted from the front to the back of the cell through the nucleus.