Roles of polymerization dynamics, opposed motors, and a tensile element in governing the length of Xenopus extract meiotic spindles
Roles of polymerization dynamics, opposed motors, and a tensile element in governing the length of Xenopus extract meiotic spindles
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DOI：
10.1091/mbc.e05-02-0174
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发表时间：
2005-06-01
影响因子：
3.3
通讯作者：
Kapoor, TM
中科院分区：
文献类型：
--
作者：
Mitchison, TJ;Maddox, P;Kapoor, TM
中期纺锤体通过涉及微管动力学和马达蛋白的机制组装成长度稳定的状态，但人们对它们的了解还不完全。我们发现，非洲爪哇提取的纺锤体利用纺锤体固有的机制概括了卵子减数分裂II纺锤体的长度。为了探索这些机制，我们扰动了微管聚合动力学和反马达蛋白，并测量了对纺锤体形态和动力学的影响。微管被己二醇和灾难因子有丝分裂着丝粒相关的动蛋白(MCAK)(一种动蛋白13，以前称为XKCM)稳定，并通过解聚药物来破坏稳定。相反的运动EG5和Dynein分别和一起被抑制。我们的结果与聚合动力学在调节纺锤体长度方面的重要作用以及相反的电机在调节双极和单极组织的相对稳定性方面的重要作用是一致的。对微管失稳的反应表明，一种未知的拉伸元件与这些常规因素平行作用，产生纺锤体缩短力。
Metaphase spindles assemble to a steady state in length by mechanisms that involve microtubule dynamics and motor proteins, but they are incompletely understood. We found that Xenopus extract spindles recapitulate the length of egg meiosis II spindles, by using mechanisms intrinsic to the spindle. To probe these mechanisms, we perturbed microtubule polymerization dynamics and opposed motor proteins and measured effects on spindle morphology and dynamics. Microtubules were stabilized by hexylene glycol and inhibition of the catastrophe factor mitotic centromere-associated kinesin (MCAK) (a kinesin 13, previously called XKCM) and destabilized by depolymerizing drugs. The opposed motors Eg5 and dynein were inhibited separately and together. Our results are consistent with important roles for polymerization dynamics in regulating spindle length, and for opposed motors in regulating the relative stability of bipolar versus monopolar organization. The response to microtubule destabilization suggests that an unidentified tensile element acts in parallel with these conventional factors, generating spindle shortening force.