Mitotic chromosome biorientation in fission yeast is enhanced by dynein and a minus-end-directed, kinesin-like protein
Mitotic chromosome biorientation in fission yeast is enhanced by dynein and a minus-end-directed, kinesin-like protein
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DOI：
10.1091/mbc.e06-11-0987
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发表时间：
2007-06-01
影响因子：
3.3
通讯作者：
McIntosh, J. Richard
中科院分区：
文献类型：
--
作者：
Grishchuk, Ekaterina L.;Spiridonov, Ilia S.;McIntosh, J. Richard
染色体生物取向，即姐妹动粒与姐妹纺锤体极的附着，对于准确的染色体分离至关重要。我们通过跟踪裂变酵母细胞中近极着丝粒的大会及其随后的后期分离来研究这一过程，这些细胞在该生物体的任何或所有负端定向、微管依赖性马达中携带缺失：两个相关的驱动蛋白 14s（Pkl1p 和 Klp2p）和动力蛋白。这些缺失都没有消除生物取向，但与野生型细胞相比，在没有 Pkl1p 的情况下正常分离的染色体更少，在没有动力蛋白的情况下分离的染色体程度也更小。由于通常位于纺锤体及其两极的 Pkl1p 缺失，监测染色体生物方向的检查点出现缺陷，导致频繁的性早熟后期。突变有丝分裂纺锤体的超微结构分析表明，Pkl1p 通过促进正常纺锤体极组织而有助于无差错生物取向，而动力蛋白有助于将一束集中的纺锤体微管锚定在极处。
Chromosome biorientation, the attachment of sister kinetochores to sister spindle poles, is vitally important for accurate chromosome segregation. We have studied this process by following the congression of pole-proximal kinetochores and their subsequent anaphase segregation in fission yeast cells that carry deletions in any or all of this organism's minus end-directed, microtubule-dependent motors: two related kinesin 14s (Pkl1p and Klp2p) and dynein. None of these deletions abolished biorientation, but fewer chromosomes segregated normally without Pkl1p, and to a lesser degree without dynein, than in wild-type cells. In the absence of Pkl1p, which normally localizes to the spindle and its poles, the checkpoint that monitors chromosome biorientation was defective, leading to frequent precocious anaphase. Ultrastructural analysis of mutant mitotic spindles suggests that Pkl1p contributes to error-free biorientation by promoting normal spindle pole organization, whereas dynein helps to anchor a focused bundle of spindle microtubules at the pole.