Analysis of heterodimer formation by Xklp3A/B, a newly cloned kinesin-II from Xenopus laevis
Analysis of heterodimer formation by Xklp3A/B, a newly cloned kinesin-II from Xenopus laevis
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DOI：
10.1093/emboj/20.13.3370
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发表时间：
2001-07-02
期刊：
影响因子：
11.4
通讯作者：
Hoenger, A
中科院分区：
文献类型：
--
作者：
De Marco, V;Burkhard, P;Hoenger, A
驱动蛋白II马达蛋白由两个不同的驱动蛋白样马达蛋白和一个货物结合亚基组成。本文报道了从非洲爪蟾（Xenopus laevis）中克隆的驱动蛋白II超家族的新成员Xklp 3A，它与Xklp 3B形成异源二聚体复合物。为此，我们制备了一系列不同长度的Xklp 3A和B构建体，并测试了它们形成异二聚体的倾向。我们可以证明，与常规驱动蛋白相反，Xklp 3A/B中异源二聚体形成的关键结构域位于柄的C末端。无论是颈部还是颈部区域后的高度带电的伸展，这是典型的驱动蛋白-II，是异源二聚体形成所必需的，也不阻止同源二聚体的形成。二聚化由C-末端卷曲螺旋片段之间的协同机制控制。未发现经典触发位点。二聚化的关键区域在驱动蛋白-II家族的等同成员中表现出非常高的序列保守性。
kinesin-II motor proteins are composed of two different kinesin-like motor proteins and one cargo binding subunit, Here we report the cloning of a new member of the kinesin-II superfamily, Xklp3A from Xenopus laevis, which forms a heterodimeric complex with Xklp3B, The heterodimer formation properties between Xklp3A and B have been tested in vitro using reticulocyte lysate expression and immnnoprecipitation, To this end we produced a series of Xklp3A and B constructs of varying length and tested their propensity for heterodimer formation. We could demonstrate that, in contrast to conventional kinesin, the critical domains for heterodimer formation in Xklp3A/B are located at the C-terminal end of the stalk. Neither the neck nor the highly charged stretches after the neck region, which are typical of kinesins-II, are required for heterodimer formation, nor do they prevent homodimer formation. Dimerization is controlled by a cooperative mechanism between the C-terminal coiled-coil segments. Classical trigger sites were not identified. The critical regions for dimerization exhibit a very high degree of sequence conservation among equivalent members of the kinesin-II family.