The Coordination of Centromere Replication, Spindle Formation, and Kinetochore-Microtubule Interaction in Budding Yeast
The Coordination of Centromere Replication, Spindle Formation, and Kinetochore-Microtubule Interaction in Budding Yeast
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DOI：
10.1371/journal.pgen.1000262
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发表时间：
2008-11-01
期刊：
影响因子：
4.5
通讯作者：
Wang, Yanchang
中科院分区：
文献类型：
--
作者：
Liu, Hong;Liang, Fengshan;Wang, Yanchang
着丝粒是一种蛋白质复合物，组装在着丝粒DNA上，介导染色体-微管相互作用。大多数真核细胞在有丝分裂过程中形成纺锤体并建立运动舞蹈-微管相互作用，但芽殖酵母细胞在S期完成这些过程。芽殖酵母S期纺锤体短于中期纺锤体的现象早已引起人们的注意，但这种短S期纺锤体结构的生物学意义尚不清楚。我们通过使用ask 1 -3解决了这个问题，ask 1 - 3是一种温度敏感的动粒突变体，在DNA合成抑制剂羟基脲（HU）的存在下，在允许的温度下表现出部分伸长的纺锤体。暴露于HU并去除HU后，ask 1 -3细胞显示延迟的后期进入。这种延迟取决于纺锤体检查点，它监测运动舞蹈微管相互作用的缺陷。微管相关蛋白Ase 1或Cin 8的过量产生也诱导了HU-停滞细胞中纺锤体的伸长。在Hu-阻滞细胞中，ASE 1或CIN 8过表达后也观察到纺锤体检查点依赖的后期进入延迟。因此，在S期细胞中较短的纺锤体可能有利于适当的染色体-微管相互作用。
The kinetochore is a protein complex that assembles on centromeric DNA to mediate chromosome-microtubule interaction. Most eukaryotic cells form the spindle and establish kinetochore-microtubule interaction during mitosis, but budding yeast cells finish these processes in S-phase. It has long been noticed that the S-phase spindle in budding yeast is shorter than that in metaphase, but the biological significance of this short S-phase spindle structure remains unclear. We addressed this issue by using ask1-3, a temperature-sensitive kinetochore mutant that exhibits partially elongated spindles at permissive temperature in the presence of hydroxyurea (HU), a DNA synthesis inhibitor. After exposure to and removal of HU, ask1-3 cells show a delayed anaphase entry. This delay depends on the spindle checkpoint, which monitors kinetochore-microtubule interaction defects. Overproduction of microtubule-associated protein Ase1 or Cin8 also induces spindle elongation in HU-arrested cells. The spindle checkpoint-dependent anaphase entry delay is also observed after ASE1 or CIN8 overexpression in HU-arrested cells. Therefore, the shorter spindle in S-phase cells is likely to facilitate proper chromosome-microtubule interaction.