Stable preanaphase spindle positioning requires Bud6p and an apparent interaction between the spindle pole bodies and the neck.
Stable preanaphase spindle positioning requires Bud6p and an apparent interaction between the spindle pole bodies and the neck.
复制标题
稳定的前期纺锤体定位需要 Bud6p 以及纺锤体极体和颈部之间的明显相互作用。
DOI：
10.1128/ec.00332-06
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Amberg,DavidC
中科院分区：
文献类型：
--
作者：
Haarer,BrianK;Helfant,AstridHoes;Nelson,ScottA;Cooper,JohnA;Amberg,DavidC
细胞分裂过程中遗传物质的忠实划分需要分裂细胞内细胞核的准确空间和时间定位。在酿酒酵母中，核定位是通过肌动蛋白和微管细胞骨架成分之间的微妙相互作用来调节的。该过程的调节因子包括 Bud6p（也称为肌动蛋白相互作用蛋白 Aip3p）和 Kar9p，其功能是促进细胞质微管末端和肌动蛋白界定的皮质附着点之间的接触。在这里，我们提出了以前未检测到的 Bud6p 与酵母纺锤体极体细胞质面的关联，酵母纺锤体极体的功能相当于后生动物中心体。缺乏Bud6p的细胞表现出母细胞和子细胞之间的细胞核运动过度，并且显示给定纺锤体极体与出芽细胞的颈部区域密切相关的时间减少。此外，在纺锤体排列缺陷的dynactin突变体中，BUD6的过度表达极大地增强了纺锤体极体和母芽颈之间的相互作用。这些结果表明，任一纺锤体极体与颈部组件的关联，而不是简单地使纺锤体极体进入子细胞，为有丝分裂的进展提供了正信号。我们认为，Bud6p 通过其在纺锤体极体和母芽颈的定位，支持这种正信号，并提供调节机制来防止前期细胞核过度振荡，从而减少有丝分裂延迟和核错误分离的可能性。
Faithful partitioning of genetic material during cell division requires accurate spatial and temporal positioning of nuclei within dividing cells. InSaccharomyces cerevisiae, nuclear positioning is regulated by an elegant interplay between components of the actin and microtubule cytoskeletons. Regulators of this process include Bud6p (also referred to as the actin-interacting protein Aip3p) and Kar9p, which function to promote contacts between cytoplasmic microtubule ends and actin-delimited cortical attachment points. Here, we present the previously undetected association of Bud6p with the cytoplasmic face of yeast spindle pole bodies, the functional equivalent of metazoan centrosomes. Cells lacking Bud6p show exaggerated movements of the nucleus between mother and daughter cells and display reduced amounts of time a given spindle pole body spends in close association with the neck region of budding cells. Furthermore, overexpression ofBUD6greatly enhances interactions between the spindle pole body and mother-bud neck in a spindle alignment-defective dynactin mutant. These results suggest that association of either spindle pole body with neck components, rather than simply entry of a spindle pole body into the daughter cell, provides a positive signal for the progression of mitosis. We propose that Bud6p, through its localization at both spindle pole bodies and at the mother-bud neck, supports this positive signal and provides a regulatory mechanism to prevent excessive oscillations of preanaphase nuclei, thus reducing the likelihood of mitotic delays and nuclear missegregation.