Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
McGill University, Montreal, QC, Canada.
EMBO J. 2023 Nov 2;42(21):e113647. doi: 10.15252/embj.2023113647. Epub 2023 Aug 18.
During mitosis, spindle architecture alters as chromosomes segregate into daughter cells. The microtubule crosslinker protein regulator of cytokinesis 1 (PRC1) is essential for spindle stability, chromosome segregation and completion of cytokinesis, but how it recruits motors to the central spindle to coordinate the segregation of chromosomes is unknown. Here, we combine structural and cell biology approaches to show that the human CENP-E motor, which is essential for chromosome capture and alignment by microtubules, binds to PRC1 through a conserved hydrophobic motif. This binding mechanism is also used by Kinesin-4 Kif4A:PRC1. Using in vitro reconstitution, we demonstrate that CENP-E slides antiparallel PRC1-crosslinked microtubules. We find that the regulation of CENP-E -PRC1 interaction is spatially and temporally coupled with relocalization to overlapping microtubules in anaphase. Finally, we demonstrate that the PRC1-microtubule motor interaction is essential in anaphase to control chromosome partitioning, retain central spindle integrity and ensure cytokinesis. Taken together our findings reveal the molecular basis for the cell cycle regulation of motor-PRC1 complexes to couple chromosome segregation and cytokinesis.
在有丝分裂过程中，纺锤体结构会随着染色体分离到子细胞中而改变。细胞分裂调控蛋白 1（PRC1）是微管交联蛋白调节剂，对于纺锤体稳定性、染色体分离和胞质分裂的完成是必不可少的，但它如何招募马达蛋白到中心纺锤体以协调染色体的分离尚不清楚。在这里，我们结合结构和细胞生物学方法表明，对于微管捕获和染色体对齐至关重要的人源中心体定位蛋白 E（CENP-E）马达蛋白通过保守的疏水性基序与 PRC1 结合。该结合机制也被驱动蛋白-4（Kinesin-4）家族的 Kif4A:PRC1 所使用。通过体外重构，我们证明 CENP-E 沿 PRC1 交联的微管反平行滑动。我们发现，CENP-E-PRC1 相互作用的调节与在后期向重叠微管的空间和时间重新定位相关联。最后，我们证明 PRC1-微管马达相互作用对于控制染色体分区、保留中心纺锤体完整性和确保胞质分裂在后期是必不可少的。总之，我们的研究结果揭示了马达-PRC1 复合物的分子基础，以协调染色体分离和胞质分裂的细胞周期调控。
