Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Carretera de Utrera, km1, 41013 Seville, Spain.
Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Carretera de Utrera, km1, 41013 Seville, Spain.
Curr Biol. 2020 Aug 17;30(16):3212-3222.e2. doi: 10.1016/j.cub.2020.05.066. Epub 2020 Jun 4.
An important question in cell biology is how cellular organelles partition during cell division. In organisms undergoing closed mitosis, the elongation of an intranuclear spindle drives nuclear division, generating two identically sized nuclei [1, 2]. However, how the site of nuclear division is determined and the underlying mechanism driving nuclear envelope (NE) fission remain largely unknown. Here, using the fission yeast, we show that the microtubule bundler Ase1/PRC1 at the spindle midzone is required for the local concentration of nuclear pore complexes (NPCs) in the region of the NE in contact with the central spindle. As the spindle elongates during anaphase B, components of these NPCs are sequentially eliminated, and this is accompanied by the local remodeling of the NE. These two events lead to the eventual removal of NPCs and nuclear division. In the absence of importin α, NPCs remain stable in this region and no event of NE remodeling is observed. Consequently, cells fail to undergo nuclear division. Thus, our results highlight a new role of the central spindle as a spatial cue that determines the site of nuclear division and point to NPC removal as the triggering event.
细胞生物学中的一个重要问题是细胞器官在细胞分裂过程中是如何分配的。在进行有丝分裂的生物中，核内纺锤体的伸长驱动核分裂，产生两个大小相同的核[1,2]。然而，核分裂的部位是如何确定的，以及驱动核膜（NE）裂变的潜在机制在很大程度上仍不清楚。在这里，我们使用裂殖酵母表明，纺锤体中部的微管束聚蛋白 Ase1/PRC1 对于与中央纺锤体接触的 NE 区域中核孔复合物（NPC）的局部集中是必需的。随着后期 B 纺锤体的伸长，这些 NPC 的成分被依次消除，同时伴随着 NE 的局部重塑。这两个事件导致 NPC 的最终去除和核分裂。在缺乏输入蛋白 α 的情况下，该区域的 NPC 保持稳定，并且没有观察到 NE 重塑事件。因此，细胞无法进行核分裂。因此，我们的结果突出了中央纺锤体作为决定核分裂部位的空间线索的新作用，并指出 NPC 的去除是触发事件。
