Architecture of the human Ndc80-Hec1 complex, a critical constituent of the outer kinetochore
Architecture of the human Ndc80-Hec1 complex, a critical constituent of the outer kinetochore
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DOI：
10.1074/jbc.m504070200
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发表时间：
2005-08-12
影响因子：
4.8
通讯作者：
Musacchio, A
中科院分区：
文献类型：
--
作者：
Ciferri, C;De Luca, J;Musacchio, A
Ndc 80复合物是着丝粒外板的组成部分，在有丝分裂中染色体分离所需的稳定的着丝粒-微管相互作用中起着关键作用。Ndc 80复合物在进化上是保守的，包含四个亚基Spc 24、Spc 25、Nuf 2和Ndc 80（其人类同源物称为Hec 1）。预测所有四个亚基都含有球状结构域和广泛的卷曲螺旋区域。为了深入了解人类Ndc 80复合物的组织，我们使用重组方法对其进行重组。重组Ndc 80复合物的流体动力学性质与内源性HeLa细胞复合物的流体动力学性质相同，并且与四个亚基的1：1：1：1化学计量和非常细长的形状一致。两个紧密的Hec 1-Nuf 2和Spc 24-Spc 25亚复合物，每个由平行的异二聚体卷曲螺旋稳定，保持这种组织。这些亚复合物分别通过Hec 1-Nuf 2和Spc 24-Spc 25卷曲螺旋的C-和N-末端部分的相互作用而四聚化。重组复合物显示正常的动粒定位后，注射在HeLa细胞中，因此是一个忠实的拷贝的内源性Ndc 80复合物。
The Ndc80 complex is a constituent of the outer plate of the kinetochore and plays a critical role in establishing the stable kinetochore-microtubule interactions required for chromosome segregation in mitosis. The Ndc80 complex is evolutionarily conserved and contains the four subunits Spc24, Spc25, Nuf2, and Ndc80 ( whose human homologue is called Hec1). All four subunits are predicted to contain globular domains and extensive coiled coil regions. To gain an insight into the organization of the human Ndc80 complex, we reconstituted it using recombinant methods. The hydrodynamic properties of the recombinant Ndc80 complex are identical to those of the endogenous HeLa cell complex and are consistent with a 1: 1: 1: 1 stoichiometry of the four subunits and a very elongated shape. Two tight Hec1-Nuf2 and Spc24-Spc25 subcomplexes, each stabilized by a parallel heterodimeric coiled coil, maintain this organization. These subcomplexes tetramerize via an interaction of the C- and N-terminal portions of the Hec1-Nuf2 and Spc24-Spc25 coiled coils, respectively. The recombinant complex displays normal kinetochore localization upon injection in HeLa cells and is therefore a faithful copy of the endogenous Ndc80 complex.