Microtubule dynamics alter the interphase nucleus
Microtubule dynamics alter the interphase nucleus
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DOI：
10.1007/s00018-012-1200-5
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发表时间：
2013-04-01
影响因子：
8
通讯作者：
Bustin, Michael
中科院分区：
文献类型：
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作者：
Gerlitz, Gabi;Reiner, Orly;Bustin, Michael
已知微管在有丝分裂和减数分裂过程中驱动染色体运动并诱导核膜破裂。在这里，我们表明，当核膜完整时，微管可以在间期期间强制核膜折叠并改变核膜相关异染色质的水平。化学诱导解聚后的微管重新组装导致核膜折叠，并导致浓缩染色质在最接近微管组织中心（MTOC）的位点短暂积累。这种微管依赖性染色质在 MTOC 附近的积累取决于核纤层的组成和动力蛋白运动蛋白的活性。我们认为，源自微管纤维同时聚合的力使核膜和下面的核膜变形。而动力蛋白运动复合体位于核膜上，沿着微管滑动，将力和/或信号传递到细胞核中，以诱导染色质重组和核膜折叠处的积累。因此，我们的研究确定了一种分子机制，细胞质中产生的机械力重塑核膜，改变染色质的核内组织，并影响间期核的结构。
Microtubules are known to drive chromosome movements and to induce nuclear envelope breakdown during mitosis and meiosis. Here we show that microtubules can enforce nuclear envelope folding and alter the levels of nuclear envelope-associated heterochromatin during interphase, when the nuclear envelope is intact. Microtubule reassembly, after chemically induced depolymerization led to folding of the nuclear envelope and to a transient accumulation of condensed chromatin at the site nearest the microtubule organizing center (MTOC). This microtubule-dependent chromatin accumulation next to the MTOC is dependent on the composition of the nuclear lamina and the activity of the dynein motor protein. We suggest that forces originating from simultaneous polymerization of microtubule fibers deform the nuclear membrane and the underlying lamina. Whereas dynein motor complexes localized to the nuclear envelope that slide along the microtubules transfer forces and/or signals into the nucleus to induce chromatin reorganization and accumulation at the nuclear membrane folds. Thus, our study identified a molecular mechanism by which mechanical forces generated in the cytoplasm reshape the nuclear envelope, alter the intranuclear organization of chromatin, and affect the architecture of the interphase nucleus.