gamma-tubulin plays an essential role in the coordination of mitotic events.
gamma-tubulin plays an essential role in the coordination of mitotic events.
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γ-微管蛋白在有丝分裂事件的协调中起着重要作用。
DOI：
10.1091/mbc.e03-06-0405
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发表时间：
2004
影响因子：
3.3
通讯作者：
Oakley,BerlR
中科院分区：
文献类型：
--
作者：
Prigozhina,NatalieL;Oakley,CElizabeth;Lewis,AmandaM;Nayak,Tania;Osmani,StephenA;Oakley,BerlR
来自多种生物体的最新数据表明，γ-微管蛋白除了使微管组装成核之外还具有重要的但不完全定义的功能。为了研究这些功能，我们检查了mipAD 159的表型，mipAD 159是构巢曲霉γ-微管蛋白基因的冷敏感等位基因。同步材料的免疫荧光显微镜显示，在限制性的温度mipAD 159不抑制有丝分裂纺锤体的形成。后期A在许多细胞核中被抑制，然而，在有丝分裂稍微延迟（细胞周期的约6%）后，大多数细胞核重新进入间期而不分裂。在限制性温度下对染色体的体内观察表明，mipAD 159导致晚期有丝分裂事件（后期A、后期B和染色体分离）的协调失败，即使有丝分裂没有成功完成，细胞核也很快重新进入间期。延时显微镜也显示，瞬时有丝分裂纺锤体异常，特别是弯曲的纺锤体，更普遍inmipAD 159株比对照组。在用苯菌灵解聚微管的实验中，mipAD 159细胞核比对照菌株的细胞核更快地退出有丝分裂（通过染色体凝聚判断）。这些数据表明，γ-微管蛋白在有丝分裂晚期事件的协调中具有重要作用，并且在有丝分裂检查点控制中具有微管非依赖性功能。
Recent data from multiple organisms indicate that γ-tubulin has essential, but incompletely defined, functions in addition to nucleating microtubule assembly. To investigate these functions, we examined the phenotype ofmipAD159, a cold-sensitive allele of the γ-tubulin gene ofAspergillus nidulans. Immunofluorescence microscopy of synchronized material revealed that at a restrictive temperaturemipAD159 does not inhibit mitotic spindle formation. Anaphase A was inhibited in many nuclei, however, and after a slight delay in mitosis (∼6% of the cell cycle period), most nuclei reentered interphase without dividing. In vivo observations of chromosomes at a restrictive temperature revealed thatmipAD159 caused a failure of the coordination of late mitotic events (anaphase A, anaphase B, and chromosomal disjunction) and nuclei reentered interphase quickly even though mitosis was not completed successfully. Time-lapse microscopy also revealed that transient mitotic spindle abnormalities, in particular bent spindles, were more prevalent inmipAD159 strains than in controls. In experiments in which microtubules were depolymerized with benomyl,mipAD159 nuclei exited mitosis significantly more quickly (as judged by chromosomal condensation) than nuclei in a control strain. These data reveal that γ-tubulin has an essential role in the coordination of late mitotic events, and a microtubule-independent function in mitotic checkpoint control.