Journal ArticleDOI
Nuclear envelope breakdown in mammalian cells involves stepwise lamina disassembly and microtubule-drive deformation of the nuclear membrane
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Nuclear envelope breakdown is not prevented when the microtubules are depolymerized by nocodazole; however, the mode of nuclear lamina fragmentation in the absence of microtubule is markedly different from the normal one and involves multiple raffles and gaps, which develop rapidly along the entire surface of the nuclear envelope.Abstract:
We have studied nuclear envelope disassembly in mammalian cells by morphological methods. The first signs of nuclear lamina depolymerization become evident in early prophase as A-type lamins start dissociating from the nuclear lamina and diffuse into the nucleoplasm. While B-type lamins are still associated with the inner nuclear membrane, two symmetrical indentations develop on antidiametric sites of the nuclear envelope. These indentations accommodate the sister centrosomes and associated astral microtubules. At mid- to late prophase, elongating microtubules apparently push on the nuclear surface and eventually penetrate the nucleus. At this point the nuclear envelope becomes freely permeable to large ligands, as indicated by experiments with digitonin-treated cells and by the massive release of solubilized A-type lamins into the cytoplasm. At the prophase/prometaphase transition, the B-type lamina is fragmented, but 'islands' of lamin B polymer can still be discerned on the tips of congressing chromosomes. Finally, at metaphase, the lamin B polymer breaks down into small pieces, which tend to concentrate in the area of the mitotic spindle. Nuclear envelope breakdown is not prevented when the microtubules are depolymerized by nocodazole; however, the mode of nuclear lamina fragmentation in the absence of microtubules is markedly different from the normal one and involves multiple raffles and gaps, which develop rapidly along the entire surface of the nuclear envelope. These data suggest that nuclear envelope disassembly is a stepwise process in which the microtubules play an important part.read more
Citations
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Journal ArticleDOI
Nuclear lamins: laminopathies and their role in premature ageing
TL;DR: It is concluded that lamins seem to be key players in, among others, controlling the process of cellular ageing, since disturbance in lamin protein structure gives rise to several forms of premature ageing.
Journal ArticleDOI
A pathway for mitotic chromosome formation
Johan H. Gibcus,Kumiko Samejima,Anton Goloborodko,Itaru Samejima,Natalia Naumova,Johannes Nuebler,Masato T. Kanemaki,Linfeng Xie,James R. Paulson,William C. Earnshaw,Leonid A. Mirny,Job Dekker +11 more
TL;DR: A pathway of mitotic chromosome folding is described that unifies many previous observations and identifies roles of specific molecular machines, condensin I and II, in these major conformational transitions.
Journal ArticleDOI
Nuclear envelope breakdown proceeds by microtubule-induced tearing of the lamina.
TL;DR: The mechanism of nuclear envelope breakdown (NEBD) was investigated in live cells, suggesting a mechanism mediated by a minus-end-directed motor.
Journal ArticleDOI
Orchestrating nuclear envelope disassembly and reassembly during mitosis.
TL;DR: These studies reveal a tight interplay between NE components and the mitotic machinery in eukaryotic cell division.
Journal ArticleDOI
Nuclear Lamins a and B1: Different Pathways of Assembly during Nuclear Envelope Formation in Living Cells
TL;DR: In later stages of G1, FRAP analyses suggest that both green fluorescent protein lamins A and B1 form higher order polymers throughout interphase nuclei.
References
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Journal ArticleDOI
The nuclear lamina is a meshwork of intermediate-type filaments.
TL;DR: The supramolecular organization of the native nuclear lamina and the structure and assembly properties of purified lamins are analysed, and it is shown that the lamins constitute a previously unrecognized class of IF polypeptides.
Journal ArticleDOI
In vitro disassembly of the nuclear lamina and M phase-specific phosphorylation of lamins by cdc2 kinase
TL;DR: It is proposed that mitotic disassembly of the nuclear lamina results from direct phosphorylation of lamins by cdc2 kinase, a major element implicated in controlling the eukaryotic cell cycle.
Journal ArticleDOI
Functional organization of the nuclear envelope
Larry Gerace,Brian Burke +1 more
TL;DR: The Nuclear Pore Complex as a Macromolecular Translocation Machine and Functions of Nuclear Localization Signals are described.
Book
Fine Structure Immunocytochemistry
TL;DR: This book describes all practical steps involved in the transition of living cells to a labelled thin section in the electron microscope and includes theoretical background to allow lab workers to modify and apply the procedures to their particular nature of work and to interpret microscopical results.
Journal ArticleDOI
Integral membrane proteins of the nuclear envelope interact with lamins and chromosomes, and binding is modulated by mitotic phosphorylation
Roland Foisner,Larry Gerace +1 more
TL;DR: Using in vitro assays, it is suggested that LAP 2 may have a key role in initial events of nuclear envelope reassembly, and that both LAP2 and LAP 1 may be involved in attaching lamins to the nuclear envelope.
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