Novel roles for Saccharomyces cerevisiae mitotic spindle motors
Novel roles for Saccharomyces cerevisiae mitotic spindle motors
复制标题
DOI：
10.1083/jcb.147.2.335
复制
发表时间：
1999-10-18
影响因子：
7.8
通讯作者：
Hoyt, MA
中科院分区：
文献类型：
--
作者：
Cottingham, FR;Gheber, L;Hoyt, MA
由酿酒酵母编码的单个细胞质动力蛋白和六种驱动蛋白相关蛋白中的五种参与有丝分裂纺锤体功能。一些马达在核内操作以组装和伸长双极纺锤体。另一些则作用于细胞质微管，影响纺锤体和细胞核在细胞内的定位。这项研究表明，驱动蛋白相关的Kar3p和Kip3p是独特的，因为它们在核内外都发挥作用。Kar3p和Kip3p一样，在动力蛋白不存在的情况下，被发现是纺锤体定位所需的。Kar3p的纺锤体定位作用与Cik1p辅助因子协同进行，而不是同源Vik1p。Kar3p和Kip3p也被发现重叠的双极纺锤体的结构完整性所必需的功能。这两个电机的细胞质和核的作用可以部分取代的微管不稳定剂苯菌灵，这表明这些电机执行一个重要的微管不稳定的功能。此外，我们发现，酵母细胞的活力可以支持少至两个微管为基础的电机：BimC型驱动蛋白Cin8p，所需的纺锤体结构，与Kar3p或Kip3p配对，所需的纺锤体结构和定位。
The single cytoplasmic dynein and five of the six kinesin-related proteins encoded by Saccharomyces cerevisiae participate in mitotic spindle function. Some of the motors operate within the nucleus to assemble and elongate the bipolar spindle. Others operate on the cytoplasmic microtubules to effect spindle and nuclear positioning within the cell. This study reveals that kinesin-related Kar3p and Kip3p are unique in that they perform roles both inside and outside the nucleus. Kar3p, like Kip3p, was found to be required for spindle positioning in the absence of dynein. The spindle positioning role of Kar3p is performed in concert with the Cik1p accessory factor, but not the homologous Vik1p. Kar3p and Kip3p were also found to overlap for a function essential for the structural integrity of the bipolar spindle. The cytoplasmic and nuclear roles of both these motors could be partially substituted for by the microtubule-destabilizing agent benomyl, suggesting that these motors perform an essential microtubule-destabilizing function. In addition, we found that yeast cell viability could be supported by as few as two microtubule-based motors: the BimC-type kinesin Cin8p, required for spindle structure, paired with either Kar3p or Kip3p, required for both spindle structure and positioning.