Astral microtubule dynamics in yeast: a microtubule-based searching mechanism for spindle orientation and nuclear migration into the bud.
Astral microtubule dynamics in yeast: a microtubule-based searching mechanism for spindle orientation and nuclear migration into the bud.
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DOI：
10.1083/jcb.139.4.985
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发表时间：
1997-11-17
影响因子：
7.8
通讯作者：
Bloom, K
中科院分区：
文献类型：
--
作者：
Shaw, SL;Yeh, E;Maddox, P;Salmon, ED;Bloom, K
动力蛋白绿色荧光蛋白（GFP）的细胞质微管的本地化，使我们能够获得在活芽殖酵母中的星形微管的动态特性的第一个视图之一。延时三维荧光显微镜揭示了微管功能的几个新方面。每极约4~6个星形微管在整个细胞周期中表现出异步的动态不稳定性，以0.3-1.5 μ m/min的速度向细胞表面生长，然后以相似的速度缩短回到纺锤体极体（SPB）。在间期，一个锥形阵列的微管落后于SPB的细胞核穿过细胞质。诺考多唑的微管分解抑制了这些运动，表明细胞核通过动态星形微管被推到细胞内部。这些突袭在未出芽的G1细胞中是明显的，以及在纺锤体解体后的末期细胞中。在S/G2或G2/M期，核向芽颈的移动和定向依赖于动态的星形微管向芽中的生长。SPB和细胞核被拉向芽颈，从SPB进一步生长的微管主要朝向芽。SPB分离和中央纺锤体形成后，细胞质动力蛋白在纺锤体两极之一的收购时间延迟是显而易见的。稳定的微管与细胞皮层的相互作用很少观察到在后期，并没有出现显着贡献纺锤体对齐或伸长到芽。在过表达动力蛋白-GFP的细胞中观察到的微管动力学的改变导致了最终的纺锤体错位。这些研究为理解纺锤体方向和核定位是如何建立的提供了第一个机制基础，并表明了一种基于微管的搜索机制，该机制需要动态微管使核迁移到芽中。
Localization of dynein–green fluorescent protein (GFP) to cytoplasmic microtubules allowed us to obtain one of the first views of the dynamic properties of astral microtubules in live budding yeast. Several novel aspects of microtubule function were revealed by time-lapse, three-dimensional fluorescence microscopy. Astral microtubules, about four to six in number for each pole, exhibited asynchronous dynamic instability throughout the cell cycle, growing at ≅0.3–1.5 μm/min toward the cell surface then switching to shortening at similar velocities back to the spindle pole body (SPB). During interphase, a conical array of microtubules trailed the SPB as the nucleus traversed the cytoplasm. Microtubule disassembly by nocodozole inhibited these movements, indicating that the nucleus was pushed around the interior of the cell via dynamic astral microtubules. These forays were evident in unbudded G1 cells, as well as in late telophase cells after spindle disassembly. Nuclear movement and orientation to the bud neck in S/G2 or G2/M was dependent on dynamic astral microtubules growing into the bud. The SPB and nucleus were then pulled toward the bud neck, and further microtubule growth from that SPB was mainly oriented toward the bud. After SPB separation and central spindle formation, a temporal delay in the acquisition of cytoplasmic dynein at one of the spindle poles was evident. Stable microtubule interactions with the cell cortex were rarely observed during anaphase, and did not appear to contribute significantly to spindle alignment or elongation into the bud. Alterations of microtubule dynamics, as observed in cells overexpressing dynein-GFP, resulted in eventual spindle misalignment. These studies provide the first mechanistic basis for understanding how spindle orientation and nuclear positioning are established and are indicative of a microtubule-based searching mechanism that requires dynamic microtubules for nuclear migration into the bud.
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DOI：
10.1083/jcb.138.3.629
发表时间：
1997-08-11
期刊：
The Journal of cell biology
影响因子：
--
作者：
Carminati JL;Stearns T
通讯作者：
Stearns T
DOI：
10.1083/jcb.105.5.2123
发表时间：
1987-11
期刊：
The Journal of cell biology
影响因子：
--
作者：
Hyman AA;White JG
通讯作者：
White JG
DOI：
10.1083/jcb.122.1.113
发表时间：
1993-07
期刊：
The Journal of cell biology
影响因子：
--
作者：
Baker J;Theurkauf WE;Schubiger G
通讯作者：
Schubiger G
影响因子：
3.2
作者：
BYERS, B;GOETSCH, L
通讯作者：
GOETSCH, L
影响因子：
56.9
作者：
Evangelista, M;Blundell, K;Boone, C
通讯作者：
Boone, C