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Nuclear envelope breakdown is coordinated by both Nup358/RanBP2 and Nup153, two nucleoporins with zinc finger modules. Mol Biol Cell 2006 Feb;17(2):760-9

Date

11/30/2005

Pubmed ID

16314393

Pubmed Central ID

PMC1356586

DOI

10.1091/mbc.e05-06-0485

Abstract

When higher eukaryotic cells transition into mitosis, the nuclear envelope, nuclear pore complexes, and nuclear lamina are coordinately disassembled. The COPI coatomer complex, which plays a major role in membrane remodeling at the Golgi, has been implicated in the process of nuclear envelope breakdown and requires interactions at the nuclear pore complex for recruitment to this new site of action at mitosis. Nup153, a resident of the nuclear pore basket, was found to be involved in COPI recruitment, but the molecular nature of the interface between COPI and the nuclear pore has not been fully elucidated. To better understand what occurs at the nuclear pore at this juncture, we have probed the role of the nucleoporin Nup358/RanBP2. Nup358 contains a repetitive zinc finger domain with overall organization similar to a region within Nup153 that is critical to COPI association, yet inspection of these two zinc finger domains reveals features that also clearly distinguish them. Here, we found that the Nup358 zinc finger domain, but not a zinc finger domain from an unrelated protein, binds to COPI and dominantly inhibits progression of nuclear envelope breakdown in an assay that robustly recapitulates this process in vitro. Moreover, the Nup358 zinc finger domain interferes with COPI recruitment to the nuclear rim. Consistent with a role for this pore protein in coordinating nuclear envelope breakdown, Nup358-specific antibodies impair nuclear disassembly. Significantly, targeting either Nup153 or Nup358 for inhibition perturbs nuclear envelope breakdown, supporting a model in which these nucleoporins play nonredundant roles, perhaps contributing to COPI recruitment platforms on both the nuclear and cytoplasmic faces of the pore. We found that an individual zinc finger is the minimal interface for COPI association, although tandem zinc fingers are optimal. These results provide new information about the critical components of nuclear membrane remodeling and lay the foundation for a better understanding of how this process is regulated.

Author List

Prunuske AJ, Liu J, Elgort S, Joseph J, Dasso M, Ullman KS

Author

Amy Jeanette Prunuske PhD Associate Professor in the Medical School Regional Campuses department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Amino Acid Sequence
Animals
Coat Protein Complex I
Coatomer Protein
Consensus Sequence
Mitosis
Models, Biological
Molecular Chaperones
Molecular Sequence Data
Nuclear Envelope
Nuclear Pore Complex Proteins
Protein Interaction Mapping
Sequence Alignment
Xenopus
Zinc Fingers
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a