在分裂过程中，真核细胞需要在两个子细胞之间准确分配其遗传材料。这个过程涉及微管有丝分裂纺锤体与染色体上被称为“着丝点”的专门区域的相互作用。Alushin等人介绍了对微管与“着丝点”的一个必要蛋白成分“Ndc80复合物”的相互作用的一项冷电子显微镜重建研究。所获结构显示，“Ndc80复合物”自身寡聚成线性阵列，后者在微管上形成一种套管一样的覆盖物，这样一种排列能够让染色体穿过微管的内在动态系统。“Ndc80复合物”与微管之间这种相互作用的性质，提出了Aurora B激酶对“着丝点”/微管相互作用进行磷调控的一个机制。。（生物谷 Bioon.com）
生物谷推荐原文出处：
Nature doi:10.1038/nature09423
The Ndc80 kinetochore complex forms oligomeric arrays along microtubules
Gregory M. Alushin,Vincent H. Ramey,Sebastiano Pasqualato,David A. Ball,Nikolaus Grigorieff,Andrea Musacchio& Eva Nogales
The Ndc80 complex is a key site of regulated kinetochore–microtubule attachment (a process required for cell division), but the molecular mechanism underlying its function remains unknown. Here we present a subnanometre-resolution cryo-electron microscopy reconstruction of the human Ndc80 complex bound to microtubules, sufficient for precise docking of crystal structures of the component proteins. We find that the Ndc80 complex binds the microtubule with a tubulin monomer repeat, recognizing α- and β-tubulin at both intra- and inter-tubulin dimer interfaces in a manner that is sensitive to tubulin conformation. Furthermore, Ndc80 complexes self-associate along protofilaments through interactions mediated by the amino-terminal tail of the NDC80 protein, which is the site of phospho-regulation by Aurora B kinase. The complex’s mode of interaction with the microtubule and its oligomerization suggest a mechanism by which Aurora B could regulate the stability of load-bearing kinetochore–microtubule attachments.
