A mechanism for nuclear positioning in fission yeast based on microtubule pushing.
A mechanism for nuclear positioning in fission yeast based on microtubule pushing.
复制标题
基于微管推动的裂变酵母中核定位的机制。
DOI：
10.1083/jcb.153.2.397
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发表时间：
2001-04-16
影响因子：
7.8
通讯作者：
Chang, F
中科院分区：
文献类型：
--
作者：
Tran, P T;Marsh, L;Doye, V;Inoue, S;Chang, F
细胞核的正确定位对于定义细胞的空间组织（例如确定细胞分裂平面）通常很重要。在间期粟酒裂殖酵母细胞中，细胞核在活跃的微管 (MT) 依赖性过程中位于圆柱形细胞的中间。在这里，我们使用绿色荧光蛋白标记来检查活细胞中 MT、纺锤体极体和核膜的动态。我们发现间期 MT 被组织成三到四个沿细胞长轴排列的反向平行 MT 束，MT 正端面向细胞尖端，负端靠近细胞中部。 MT 束由内侧 MT 组织中心组织而成，可充当核附着位点。当 MT 生长到细胞尖端时，它们会施加正端 MT 聚合产生的瞬时力，推动细胞核。在细胞尖端平均生长 1.5 分钟后，MT plus 末端表现出灾难性并收缩回核区域，然后再生长回细胞尖端。计算机模型表明，这些 MT 推动力的平衡可以提供一种将细胞核定位在细胞中部的机制。
The correct positioning of the nucleus is often important in defining the spatial organization of the cell, for example, in determining the cell division plane. In interphase Schizosaccharomyces pombe cells, the nucleus is positioned in the middle of the cylindrical cell in an active microtubule (MT)-dependent process. Here, we used green fluorescent protein markers to examine the dynamics of MTs, spindle pole body, and the nuclear envelope in living cells. We find that interphase MTs are organized in three to four antiparallel MT bundles arranged along the long axis of the cell, with MT plus ends facing both the cell tips and minus ends near the middle of the cell. The MT bundles are organized from medial MT-organizing centers that may function as nuclear attachment sites. When MTs grow to the cell tips, they exert transient forces produced by plus end MT polymerization that push the nucleus. After an average of 1.5 min of growth at the cell tip, MT plus ends exhibit catastrophe and shrink back to the nuclear region before growing back to the cell tip. Computer modeling suggests that a balance of these pushing MT forces can provide a mechanism to position the nucleus at the middle of the cell.