Dultz, E. et al. Systematic kinetic analysis of mitotic dis- and reassembly of the nuclear pore in living cells. J. Cell Biol. 180, 857-865

Gene Expression Unit, European Molecular Biology Laboratory, D-69117 Heidelberg, Germany.
The Journal of Cell Biology (Impact Factor: 9.83). 04/2008; 180(5):857-65. DOI: 10.1083/jcb.200707026
Source: PubMed


During mitosis in higher eukaryotes, nuclear pore complexes (NPCs) disassemble in prophase and are rebuilt in anaphase and telophase. NPC formation is hypothesized to occur by the interaction of mitotically stable subcomplexes that form defined structural intermediates. To determine the sequence of events that lead to breakdown and reformation of functional NPCs during mitosis, we present here our quantitative assay based on confocal time-lapse microscopy of single dividing cells. We use this assay to systematically investigate the kinetics of dis- and reassembly for eight nucleoporin subcomplexes relative to nuclear transport in NRK cells, linking the assembly state of the NPC with its function. Our data establish that NPC assembly is an ordered stepwise process that leads to import function already in a partially assembled state. We furthermore find that nucleoporin dissociation does not occur in the reverse order from binding during assembly, which may indicate a distinct mechanism.

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    • " endoplasmic reticulum ( ER ) ex - tensions , which initiate interactions between chromatin and inner nuclear membrane proteins ( Anderson and Hetzer , 2008 ; Lu et al . , 2011 ) . Membrane fusion of nuclear envelope microdomains and nuclear pore complex assembly complete NEF to build a fully func - tioning nuclear envelope ( Baur et al . , 2007 ; Dultz et al . , 2008 ) . Chro - matin decondensation is concomitant with NEF , and Aurora B has been shown to inhibit both decondensation and NEF on a global scale ( Ramadan et al . , 2007 ; Meyer et al . , 2010 ; Afonso et al . , 2014 ) ."
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    ABSTRACT: To determine how chromosome segregation is coordinated with nuclear envelope formation (NEF), we examined the dynamics of NEF in the presence of lagging acentric chromosomes in Drosophila neuroblasts. Acentric chromosomes often exhibit delayed but ultimately successful segregation and incorporation into daughter nuclei. However, it is unknown whether these late segregating acentric fragments influence NEF to ensure their inclusion in daughter nuclei. Through live analysis, we show that acentric chromosomes induce highly localized delays in the reassembly of the nuclear envelope. These delays result in a gap in the nuclear envelope that facilitates the inclusion of lagging acentrics into telophase daughter nuclei. Localized delays of nuclear envelope reassembly require Aurora B kinase activity. In cells with reduced Aurora B activity, there is a decrease in the frequency of local nuclear envelope reassembly delays, resulting in an increase in the frequency of acentric-bearing lamin-coated micronuclei. These studies reveal a novel role of Aurora B for maintaining genomic integrity by promoting the formation of a passageway in the nuclear envelope through which late segregating acentric chromosomes enter the telophase daughter nucleus. © 2015 by The American Society for Cell Biology.
    Molecular biology of the cell 04/2015; 26(12). DOI:10.1091/mbc.E15-01-0026 · 4.47 Impact Factor
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    • "Molecular Biology of the Cell Moreover, A. nidulans Nup2 translocates to the main chromatin region from NPCs during mitosis (Osmani et al., 2006a), a transition conserved in rat kidney cells (Dultz et al., 2008). A study also identified Nup50 in the protein composition of mitotic chromosomes (Ohta et al., 2010). "
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    ABSTRACT: Chromatin and nuclear pore complexes (NPCs) undergo dramatic changes during mitosis which in vertebrates and Aspergillus nidulans involves movement of Nup2 from NPCs to the chromatin region to fulfill unknown functions. This transition is shown to require the Cdk1 mitotic kinase and to be promoted prematurely by ectopic expression of the NIMA kinase. Nup2 localizes with a copurifying partner termed NupA, a highly divergent yet essential NPC protein. NupA and Nup2 locate throughout the chromatin region during prophase but during anaphase move to surround segregating DNA. NupA function is shown to involve targeting Nup2 to its interphase and mitotic locations. Deletion of either Nup2 or NupA causes identical mitotic defects that initiate a spindle assembly checkpoint (SAC) dependent mitotic delay and also cause defects in karyokinesis. These mitotic problems are not caused either by overall defects in mitotic NPC disassembly-reassembly or general nuclear import. However, without Nup2 or NupA, although the SAC protein Mad1 locates to its mitotic locations it fails to locate to NPCs normally in G1 after mitosis. Collectively the study provides new insight to the roles of Nup2 and NupA during mitosis and in a surveillance mechanism that regulates nucleokinesis when mitotic defects occur after SAC fulfillment. © 2014 by The American Society for Cell Biology.
    Molecular Biology of the Cell 12/2014; 26(4). DOI:10.1091/mbc.E14-09-1359 · 4.47 Impact Factor
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    • "Nup93 subsequently recruits the FG repeat-containing nucleoporins of the Nup62 complex. The FG-containing nucleoporin Nup98 is recruited concomitantly with Nup93 (Dultz et al. 2008) and has recently been found to be key to the establishment of the transport and exclusion properties of the pore (Hulsmann et al. 2012; Laurell et al. 2011). Together, these FG nucleoporins form a substantial part of the hydrophobic meshwork in the center of the pore (Ribbeck and Gorlich 2001). "
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