Membrane-coating lattice scaffolds in the nuclear pore and vesicle coats: Commonalities, differences, challenges

The nuclear pore complex (NPC) regulates all traffic between the cytoplasm and the nucleus. It is a large protein assembly composed of multiple copies of ~30 nucleoporins (nups). Structural studies of the NPC have been limited by its considerable size and complexity. Progress toward understanding t...

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Bibliographic Details
Main Authors: Leksa, Nina Carolina, Schwartz, Thomas
Other Authors: Massachusetts Institute of Technology. Department of Biology
Format: Article
Language:en_US
Published: Landes Bioscience 2014
Online Access:http://hdl.handle.net/1721.1/85064
https://orcid.org/0000-0001-8012-1512
Description
Summary:The nuclear pore complex (NPC) regulates all traffic between the cytoplasm and the nucleus. It is a large protein assembly composed of multiple copies of ~30 nucleoporins (nups). Structural studies of the NPC have been limited by its considerable size and complexity. Progress toward understanding the structure of this nanomachine has benefited from its modular nature, which allows for this 40-60 MDa assembly to be broken down into subcomplexes that can be studied individually. While recent work by both crystallographers and electron microscopists has greatly enhanced our model of the NPC, the resolution gap between crystal and EM structures remains too large to confidently place individual proteins within the context of the fully assembled NPC. In an effort to arrive at a veritable model of the NPC, we solved the structure of several scaffold nups and defined the ancestral coatomer element (ACE1) common to a set of nucleoporins and COPII vesicle coat proteins. Subsequently, we proposed a lattice-like model of the NPC, analogous to the COPII lattice, in which ACE1 proteins form the edge elements and β-propellers form the vertex elements. Here, we review our recent studies, speculate on how interactions between subcomplexes of the NPC are mediated, and outline the steps and challenges that lay ahead on the path to understanding this enormous assembly in molecular detail.