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Published on: August 13, 2016
The Nup107-160 nucleoporin complex is required for correct bipolar spindle assembly
Arturo V Orjalo1, Alexei Arnaoutov, Zhouxin Shen
1Sections of Cell and Developmental Biology, Division of Biological Sciences, University of California-San Diego Medical School, La Jolla, CA 92093-0347, USA.
Molecular Biology of the Cell
|June 30, 2006
Summary
The Nup107-160 complex, a nuclear pore component, is vital for mitotic spindle assembly in human cells. Its depletion disrupts microtubule organization, highlighting a novel role beyond nuclear pore function.
Area of Science:
- Cell Biology
- Molecular Biology
- Cytoskeleton Dynamics
Background:
- The Nup107-160 complex is a key component of the nuclear pore.
- Its role in mammalian mitotic cells, particularly at kinetochores, remains largely uncharacterized.
- The complex exhibits dual localization at kinetochores and spindle poles during prometaphase.
Purpose of the Study:
- To investigate the function of the Nup107-160 complex during mitosis.
- To determine the mechanism of Nup107-160 complex recruitment to kinetochores.
- To elucidate the complex's role in spindle assembly and checkpoint function.
Main Methods:
- Immunostaining of human cells with antibodies against Nup107-160 complex components.
- Analysis of Nup107-160 complex localization at kinetochores and spindle structures.
- Depletion of the Nup107-160 complex from Xenopus egg extracts to assess its impact on spindle assembly.
- Microtubule nucleation and assembly assays in depleted extracts.
Main Results:
- The Nup107-160 complex localizes to kinetochores and spindle poles during prometaphase, mirroring spindle checkpoint proteins.
- Expanded crescents of the complex surround unattached kinetochores.
- Depletion of the complex in Xenopus extracts leads to defective spindle assembly, with microtubules rapidly disassembling.
- The spindle checkpoint remains functional, and Ran-GTP-mediated aster formation is unaffected.
Conclusions:
- The Nup107-160 complex is dynamically involved in mitosis.
- It plays a crucial role in promoting spindle assembly, independent of its nuclear pore functions.
- This study reveals a novel function of the Nup107-160 complex in microtubule organization during cell division.
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