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Nup358 integrates nuclear envelope breakdown with kinetochore assembly.
Davide Salina1, Paul Enarson, J B Rattner
1Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL 32610-0235, USA.
The Journal of Cell Biology
|September 10, 2003
Summary
Nuclear envelope breakdown (NEBD) is crucial for mitosis. The protein Nup358 is essential for kinetochore function after NEBD, ensuring proper chromosome segregation.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Nuclear envelope breakdown (NEBD) and chromosome release into the cytoplasm are critical early mitotic events in metazoans.
- Nuclear pore complexes (NPCs) disassemble during NEBD, with some subunits relocating to kinetochores.
- The protein Nup358 is one such NPC subunit found at kinetochores post-NEBD.
Purpose of the Study:
- To investigate the role of Nup358 in mitosis after nuclear envelope breakdown.
- To determine the impact of Nup358 depletion on kinetochore function and chromosome segregation.
Main Methods:
- RNA interference (siRNA)-mediated depletion of Nup358 in metazoan cells.
- Microscopy and biochemical assays to assess kinetochore structure, chromosome congression, and segregation.
- Analysis of mitotic progression and checkpoint activity.
Main Results:
- Depletion of Nup358 severely perturbs chromosome congression and segregation.
- Nup358 absence inhibits the assembly of other kinetochore components, leading to aberrant kinetochore structure.
- Cells depleted of Nup358 exhibit mitotic arrest, suggesting potential persistent mitotic checkpoint activity at non-kinetochore sites.
Conclusions:
- Nup358 is essential for integrating nuclear envelope breakdown with kinetochore maturation and function.
- Nup358 plays a critical role in ensuring accurate chromosome segregation during mitosis.
- Aberrant mitotic progression and checkpoint activity in Nup358-depleted cells highlight its multifaceted role in cell division.