Cytokinesis and midzone microtubule organization in Caenorhabditis elegans require the kinesin-like protein ZEN-4
Cytokinesis and midzone microtubule organization in Caenorhabditis elegans require the kinesin-like protein ZEN-4
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DOI：
10.1091/mbc.9.8.2037
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发表时间：
1998-08-01
影响因子：
3.3
通讯作者：
Hardin, J
中科院分区：
文献类型：
--
作者：
Raich, WB;Moran, AN;Hardin, J
驱动蛋白马达蛋白MKLP 1亚家族的成员定位于纺锤体中间区的赤道区域，并且能够在体外捆绑反平行微管。尽管有这些有趣的特征，但目前还不清楚这些驱动蛋白在细胞分裂中发挥什么作用，特别是在发育中的胚胎中。在这里，我们报告了一个无效等位基因的zen-4，MKLP 1同源线虫的鉴定，并证明ZEN-4是必不可少的胞质分裂。被剥夺ZEN-4的胚胎形成多核单细胞胚胎，因为它们继续通过有丝分裂循环，但未能完成细胞分裂。细胞动力学沟的起始发生在正常的时间和地点，但沟的繁殖过早地停止。时间推移记录和微管染色显示，胞质分裂缺陷之前的中间区微管的解离。我们发现，ZEN-4蛋白定位于纺锤体中间区在后期，并持续在整个胞质分裂的中体区域。我们建议，ZEN-4直接交联的中间区微管，并建议这些微管是完成胞质分裂所必需的。
Members of the MKLP1 subfamily of kinesin motor proteins localize to the equatorial region of the spindle midzone and are capable of bundling antiparallel microtubules in vitro. Despite these intriguing characteristics, it is unclear what role these kinesins play in dividing cells, particularly within the context of a developing embryo. Here, we report the identification of a null allele of zen-4, an MKLP1 homologue in the nematode Caenorhabditis elegans, and demonstrate that ZEN-4 is essential for cytokinesis. Embryos deprived of ZEN-4 form multinucleate single-celled embryos as they continue to cycle through mitosis but fail to complete cell division. Initiation of the cytokinetic furrow occurs at the normal time and place, but furrow propagation halts prematurely. Timelapse recordings and microtubule staining reveal that the cytokinesis defect is preceded by the dissociation of the midzone microtubules. We show that ZEN-4 protein localizes to the spindle midzone during anaphase and persists at the midbody region throughout cytokinesis. We propose that ZEN-4 directly cross-links the midzone microtubules and suggest that these microtubules are required for the completion of cytokinesis.