MKLP2 Is a Motile Kinesin that Transports the Chromosomal Passenger Complex during Anaphase
MKLP2 Is a Motile Kinesin that Transports the Chromosomal Passenger Complex during Anaphase
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DOI：
10.1016/j.cub.2020.04.081
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发表时间：
2020-07-06
期刊：
影响因子：
9.2
通讯作者：
Lens, Susanne M. A.
中科院分区：
文献类型：
--
作者：
Adriaans, Ingrid E.;Hooikaas, Peter Jan;Lens, Susanne M. A.
在胞质分裂期间，来自后期纺锤体的信号指导细胞皮质处收缩环的形成和定位[1]。染色体乘客复合体（CPC）通过来自纺锤体中间区和赤道皮质的信号传导参与胞质分裂起始[2]，但后期特异性CPC定位的潜在机制目前尚未解决。CPC在这些位点的积累需要微管和有丝分裂驱动蛋白样蛋白2 MKLP 2（KIF 20 A）（驱动蛋白-6家族的成员）的存在[2-7]，这导致了CPC通过MKLP 2沿着微管转运的假设[3-5，7]。然而，MKLP 2马达结构域及其延伸的颈连接区的结构表明，这种驱动蛋白可能无法驱动进行性运输[8，9]。此外，在非洲爪蟾卵提取物中的实验表明CPC可能通过驱动蛋白-4，KIF 4A转运[10]。最后，CPC-MKLP 2复合物可能通过与肌动蛋白和肌球蛋白II的结合直接募集到赤道皮质，而不依赖于驱动蛋白活性[4，8]。使用显微镜为基础的分析与纯化的蛋白质，我们表明，MKLP 2是一个进行性加端定向电机，可以运输的CPC沿着微管在体外。在细胞中，MKLP 2依赖性CPC运动性的MKLP 2 P环突变体的表达强烈抑制扰乱了CPC在纺锤体中间区和赤道皮质的积累，而使用Paprotrain对MKLP 2马达的较弱抑制主要影响CPC在赤道皮质的定位。我们的数据表明，控制胞质分裂起始的CPC需要其定向MKLP 2依赖性运输。
During cytokinesis, signals from the anaphase spindle direct the formation and position of a contractile ring at the cell cortex [1]. The chromosomal passenger complex (CPC) participates in cytokinesis initiation by signaling from the spindle midzone and equatorial cortex [2], but the mechanisms underlying the anaphase-specific CPC localization are currently unresolved. Accumulation of the CPC at these sites requires the presence of microtubules and the mitotic kinesin-like protein 2, MKLP2 (KIF20A), a member of the kinesin-6 family [2-7], and this has led to the hypothesis that the CPC is transported along microtubules by MKLP2 [3-5, 7]. However, the structure of the MKLP2 motor domain with its extended neck-linker region suggests that this kinesin might not be able to drive processive transport [8, 9]. Furthermore, experiments in Xenopus egg extracts indicated that the CPC might be transported by kinesin-4, KIF4A [10]. Finally, CPC-MKLP2 complexes might be directly recruited to the equatorial cortex via association with actin and myosin II, independent of kinesin activity [4, 8]. Using microscopy-based assays with purified proteins, we demonstrate that MKLP2 is a processive plus-end directed motor that can transport the CPC along microtubules in vitro. In cells, strong suppression of MKLP2-dependent CPC motility by expression of an MKLP2 P-loop mutant perturbs CPC accumulation at both the spindle midzone and equatorial cortex, whereas a weaker inhibition of MKLP2 motor using Paprotrain mainly affects CPC localization to the equatorial cortex. Our data indicate that control of cytokinesis initiation by the CPC requires its directional MKLP2-dependent transport.