De Simone Alessandro, Nédélec François, Gönczy Pierre
Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland.
Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany.
Cell Rep. 2016 Mar 8;14(9):2250-2262. doi: 10.1016/j.celrep.2016.01.077. Epub 2016 Feb 25.
The two centrosomes present at the onset of mitosis must separate in a timely and accurate fashion to ensure proper bipolar spindle assembly. The minus-end-directed motor dynein plays a pivotal role in centrosome separation, but the underlying mechanisms remain elusive, particularly regarding how dynein coordinates this process in space and time. We addressed these questions in the one-cell C. elegans embryo, using a combination of 3D time-lapse microscopy and computational modeling. Our analysis reveals that centrosome separation is powered by the joint action of dynein at the nuclear envelope and at the cell cortex. Strikingly, we demonstrate that dynein at the cell cortex acts as a force-transmitting device that harnesses polarized actomyosin cortical flows initiated by the centrosomes earlier in the cell cycle. This mechanism elegantly couples cell polarization with centrosome separation, thus ensuring faithful cell division.
有丝分裂开始时存在的两个中心体必须及时、准确地分离，以确保正确组装双极纺锤体。向负端移动的动力蛋白驱动蛋白在中心体分离中起关键作用，但其潜在机制仍不清楚，特别是关于驱动蛋白如何在空间和时间上协调这一过程。我们在单细胞秀丽隐杆线虫胚胎中，结合三维延时显微镜和计算模型来解决这些问题。我们的分析表明，中心体分离是由核膜和细胞皮层处的驱动蛋白共同作用驱动的。引人注目的是，我们证明细胞皮层处的驱动蛋白作为一种力传递装置，利用细胞周期早期由中心体引发的极化肌动球蛋白皮层流。这种机制巧妙地将细胞极化与中心体分离联系起来，从而确保细胞的准确分裂。
