During cell division, misaligned chromosomes are captured and aligned by motors before their segregation. The CENP-E motor is recruited to polar unattached kinetochores to facilitate chromosome alignment. The spindle checkpoint protein BubR1 (also known as BUB1B) has been reported as a CENP-E interacting partner, but the extent to which BubR1 contributes to CENP-E localization at kinetochores has remained controversial. Here we define the molecular determinants that specify the interaction between BubR1 and CENP-E. The basic C-terminal helix of BubR1 is necessary but not sufficient for CENP-E interaction, and a minimal key acidic patch on the kinetochore-targeting domain of CENP-E is also essential. We then demonstrate that BubR1 is required for the recruitment of CENP-E to kinetochores to facilitate chromosome alignment. This BubR1–CENP-E axis is critical for alignment of chromosomes that have failed to congress through other pathways and recapitulates the major known function of CENP-E. Overall, our studies define the molecular basis and the function for CENP-E recruitment to BubR1 at kinetochores during mammalian mitosis.

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在细胞分裂过程中，错位的染色体在分离之前被马达捕获并对齐。 CENP-E 马达被招募到极地独立着丝粒以促进染色体对齐。纺锤体检查点蛋白 BubR1（也称为 BUB1B）已被报道为 CENP-E 相互作用伙伴，但 BubR1 对 CENP-E 在着丝粒定位的贡献程度仍存在争议。在这里，我们定义了指定 BubR1 和 CENP-E 之间相互作用的分子决定因素。 BubR1 的基本 C 末端螺旋对于 CENP-E 相互作用是必要的，但还不够，并且 CENP-E 着丝粒靶向结构域上的最小关键酸性补丁也是必需的。然后我们证明 BubR1 是招募 CENP-E 到动粒以促进染色体排列所必需的。该 BubR1-CENP-E 轴对于未能通过其他途径聚集的染色体的排列至关重要，并概括了 CENP-E 的主要已知功能。总体而言，我们的研究定义了哺乳动物有丝分裂期间 CENP-E 募集到动粒 BubR1 的分子基础和功能。

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