Nucleocytoplasmic sorting of macromolecules following mitosis: fate of nuclear constituents after inhibition of pore complex function.
Nucleocytoplasmic sorting of macromolecules following mitosis: fate of nuclear constituents after inhibition of pore complex function.
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有丝分裂后大分子的核细胞质排序：抑制孔复合体功能后核成分的命运。
DOI：
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发表时间：
1989
影响因子：
6.6
通讯作者：
N. Chaly
中科院分区：
文献类型：
--
作者：
R. Benavente;U. Scheer;N. Chaly
在有丝分裂早期通过显微注射单克隆抗体（对Mr 68，000孔复合物糖蛋白具有特异性）或麦胚凝集素（WGA）阻断孔复合物介导的转运的PtK2细胞完成胞质分裂。然而，它们的细胞核仍然稳定地被逮捕在一个末期样的组织，其特征在于高度浓缩的染色质和核仁的情况下，表明需要孔介导的运输的间期核的重组。我们现在已经通过使用免疫荧光显微镜监测显微注射细胞中单个核大分子的行为来更密切地研究了这一要求，并研究了显微注射抗体或WGA对细胞超微结构的影响。核运输的情况下，并没有影响到子细胞核的成分，如DNA，DNA拓扑异构酶I和核仁蛋白原纤蛋白，进行有丝分裂染色体上的隔离。另一方面，核纤层蛋白，snRNA和p68孔复合物糖蛋白，所有细胞质在有丝分裂期间，仍然主要是细胞质中的末期停滞的细胞。电子显微镜显示细胞核被双层膜包围，膜上有一些插入的孔复合物。此外，然而，各种膜结构与相关的孔复合物定期注意到在细胞质中，这表明染色质可能不是必不可少的有丝分裂后孔复合物的形成。我们提出细胞在末期的区室化是一个两步的过程。首先，核被膜紧紧地包裹着浓缩的染色体，非选择性地排除所有与染色体无关的大分子。间期核组织，然后逐步恢复选择性孔复合体介导的核蛋白质从细胞质的摄取。
PtK2 cells in which pore complex-mediated transport is blocked by microinjection early in mitosis of a monoclonal antibody (specific for an Mr 68,000 pore complex glycoprotein) or of wheat germ agglutinin (WGA) complete cytokinesis. However, their nuclei remain stably arrested in a telophase-like organization characterized by highly condensed chromatin and the absence of nucleoli, indicating a requirement for pore-mediated transport for the reassembly of interphase nuclei. We have now examined this requirement more closely by monitoring the behavior of individual nuclear macromolecules in microinjected cells using immunofluorescence microscopy and have investigated the effect of microinjecting the antibody or WGA on cellular ultrastructure. The absence of nuclear transport did not affect the sequestration into daughter nuclei of components such as DNA, DNA topoisomerase I and the nucleolar protein fibrillarin that are carried through mitosis on chromosomes. On the other hand, lamins, snRNAs and the p68 pore complex glycoprotein, all cytoplasmic during mitosis, remained largely cytoplasmic in the telophase-arrested cells. Electron microscopy showed the nuclei to be surrounded by a double-layered membrane with some inserted pore complexes. In addition, however, a variety of membranous structures with associated pore complexes was regularly noted in the cytoplasm, suggesting that chromatin may not be essential for the postmitotic formation of pore complexes. We propose that cellular compartmentalization at telophase is a two-step process. First, a nuclear envelope tightly encloses the condensed chromosomes, excluding non-selectively all macromolecules not associated with the chromosomes. Interphase nuclear organization is then progressively restored by selective pore complex-mediated uptake of nuclear proteins from the cytoplasm.
细胞核：结构、功能和动力学。
影响因子：
16.6
作者：
Newport,JW;Forbes,DJ
通讯作者：
Forbes,DJ
影响因子：
56.9
作者：
SHERO, JH;BORDWELL, B;EARNSHAW, WC
通讯作者：
EARNSHAW, WC