Kinesins klp5(+) and klp6(+) are required for normal chromosome movement in mitosis.
Kinesins klp5(+) and klp6(+) are required for normal chromosome movement in mitosis.
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发表时间：
2002-03
影响因子：
4
通讯作者：
R. West;T. Malmstrom;J. McIntosh
中科院分区：
文献类型：
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作者：
R. West;T. Malmstrom;J. McIntosh
正确的有丝分裂染色体分离需要纺锤体微管和着丝点之间的动态相互作用。在这里，我们证明了两个相关的分裂酵母驱动蛋白，klp5（+）和klp6(+)，是有丝分裂中正常染色体分离所必需的。零突变体通常缺乏正常的中期染色体排列。在姐妹染色单体分离之前，染色体对沿着纺体来回移动很长一段时间，这种表型使人联想到后生动物中CENP-E的丢失。最终，姐妹染色单体分离，无论染色体沿纺锤体的位置如何，并且通常产生有活力的子细胞。后期B的起始有时延迟，但纺锤体伸长率与野生型相似。尽管有延迟，后期B经常在后期a完成之前开始。klp5Delta和klp6Delta零突变体通过缺失纺锤体组装检查点基因bub1（+）、后期促进复合体成分中的几个突变体以及着丝点和微管结合蛋白Dis1p的冷敏感等位基因而具有合成致死性。Klp5p- gfp和Klp6p- gfp从前期到后期A开始定位到着丝点，但在后期b重新定位到纺锤体中间区。这些数据表明，Klp5p和Klp6p是前中期正常染色体运动所必需的着丝点激酶。
Proper mitotic chromosome segregation requires dynamic interactions between spindle microtubules and kinetochores. Here we demonstrate that two related fission yeast kinesins, klp5(+) and klp6(+), are required for normal chromosome segregation in mitosis. Null mutants frequently lack a normal metaphase chromosome alignment. Chromosome pairs move back and forth along the spindle for an extended period prior to sister chromatid separation, a phenotype reminiscent of the loss of CENP-E in metazoans. Ultimately, sister chromatids segregate, regardless of chromosome position along the spindle, and viable daughter cells are usually produced. The initiation of anaphase B is sometimes delayed, but the rate of spindle elongation is similar to wildtype. Despite a delay, anaphase B often begins before anaphase A is completed. The klp5Delta and klp6Delta null mutants are synthetically lethal with a deletion of the spindle assembly checkpoint gene, bub1(+), several mutants in components of the anaphase promoting complex, and a cold sensitive allele of the kinetochore and microtubule-binding protein, Dis1p. Klp5p-GFP and Klp6p-GFP localize to kinetochores from prophase to the onset of anaphase A, but relocalize to the spindle midzone during anaphase B. These data indicate that Klp5p and Klp6p are kinetochore kinesins required for normal chromosome movement in prometaphase.