Molecular and structural analysis of central transport channel in complex with Nup93 of nuclear pore complex

The basket of the nuclear pore complex (NPC) is generally depicted as a discrete structure of eight protein filaments that protrude into the nucleoplasm and converge in a ring distal to the NPC. We show that the yeast proteins Mlp1p and Mlp2p are necessary components of the nuclear basket and that they also embed the NPC within a dynamic protein network, whose extended interactome includes the spindle organizer, silencing factors, the proteasome, and key components of messenger ribonucleoproteins (mRNPs). Ultrastructural observations indicate that the basket reduces chromatin crowding around the central transporter of the NPC and might function as a docking site for mRNP during nuclear export. In addition, we show that the Mlps contribute to NPC positioning, nuclear stability, and nuclear envelope morphology. Our results suggest that the Mlps are multifunctional proteins linking the nuclear transport channel to multiple macromolecular complexes involved in the regulation of gene expression and chromatin maintenance.

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Architecture of the fungal nuclear pore inner ring complex

Science ◽

10.1126/science.aac9176 ◽

2015 ◽

Vol 350 (6256) ◽

pp. 56-64 ◽

Cited By ~ 58

Author(s):

Tobias Stuwe ◽

Christopher J. Bley ◽

Karsten Thierbach ◽

Stefan Petrovic ◽

Sandra Schilbach ◽

...

Keyword(s):

Nuclear Pore Complex ◽

Diffusion Barrier ◽

Three Dimensional ◽

Interaction Network ◽

Nucleocytoplasmic Transport ◽

Nuclear Pore ◽

Transport Channel ◽

Ring Complex ◽

And Diffusion

The nuclear pore complex (NPC) constitutes the sole gateway for bidirectional nucleocytoplasmic transport. We present the reconstitution and interdisciplinary analyses of the ~425-kilodalton inner ring complex (IRC), which forms the central transport channel and diffusion barrier of the NPC, revealing its interaction network and equimolar stoichiometry. The Nsp1•Nup49•Nup57 channel nucleoporin heterotrimer (CNT) attaches to the IRC solely through the adaptor nucleoporin Nic96. The CNT•Nic96 structure reveals that Nic96 functions as an assembly sensor that recognizes the three-dimensional architecture of the CNT, thereby mediating the incorporation of a defined CNT state into the NPC. We propose that the IRC adopts a relatively rigid scaffold that recruits the CNT to primarily form the diffusion barrier of the NPC, rather than enabling channel dilation.

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In situ structural analysis of the human nuclear pore complex

Nature ◽

10.1038/nature15381 ◽

2015 ◽

Vol 526 (7571) ◽

pp. 140-143 ◽

Cited By ~ 205

Author(s):

Alexander von Appen ◽

Jan Kosinski ◽

Lenore Sparks ◽

Alessandro Ori ◽

Amanda L. DiGuilio ◽

...

Keyword(s):

Structural Analysis ◽

Nuclear Pore Complex ◽

Nuclear Pore

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Construction of A High‐flux Protein Transport Channel Inspired by the Nuclear Pore Complex

Angewandte Chemie International Edition ◽

10.1002/anie.202110273 ◽

2021 ◽

Author(s):

Lei Yang ◽

Ming Cheng ◽

Jiaxin Quan ◽

Siyun Zhang ◽

Lu Liu ◽

...

Keyword(s):

Nuclear Pore Complex ◽

Protein Transport ◽

Nuclear Pore ◽

High Flux ◽

Transport Channel

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Structural analysis of the nuclear pore complex by integrated approaches

Current Opinion in Structural Biology ◽

10.1016/j.sbi.2009.02.009 ◽

2009 ◽

Vol 19 (2) ◽

pp. 226-232 ◽

Cited By ~ 47

Author(s):

Nadav Elad ◽

Tal Maimon ◽

Daphna Frenkiel-Krispin ◽

Roderick YH Lim ◽

Ohad Medalia

Keyword(s):

Structural Analysis ◽

Nuclear Pore Complex ◽

Nuclear Pore ◽

Integrated Approaches

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Faculty Opinions recommendation of Integrated structural analysis of the human nuclear pore complex scaffold.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718198609.793488044 ◽

2013 ◽

Author(s):

Thomas Schwartz

Keyword(s):

Structural Analysis ◽

Nuclear Pore Complex ◽

Nuclear Pore

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Dissecting Torsin/cofactor function at the nuclear envelope: a genetic study

Molecular Biology of the Cell ◽

10.1091/mbc.e16-07-0511 ◽

2016 ◽

Vol 27 (25) ◽

pp. 3964-3971 ◽

Cited By ~ 39

Author(s):

Ethan Laudermilch ◽

Pei-Ling Tsai ◽

Morven Graham ◽

Elizabeth Turner ◽

Chenguang Zhao ◽

...

Keyword(s):

Electron Microscopy ◽

Structural Analysis ◽

Nuclear Envelope ◽

Nuclear Pore Complex ◽

Compositional Analysis ◽

Immunogold Labeling ◽

Nuclear Pore ◽

Functional Link ◽

Experimental Platform ◽

Bleb Formation

The human genome encodes four Torsin ATPases, the functions of which are poorly understood. In this study, we use CRISPR/Cas9 engineering to delete all four Torsin ATPases individually and in combination. Using nuclear envelope (NE) blebbing as a phenotypic measure, we establish a direct correlation between the number of inactivated Torsin alleles and the occurrence of omega-shaped herniations within the lumen of the NE. A similar, although not identical, redundancy is observed for LAP1 and LULL1, which serve as regulatory cofactors for a subset of Torsin ATPases. Unexpectedly, deletion of Tor2A in a TorA/B/3A-deficient background results in a stark increase of bleb formation, even though Tor2A does not respond to LAP1/LULL1 stimulation. The robustness of the observed phenotype in Torsin-deficient cells enables a structural analysis via electron microscopy tomography and a compositional analysis via immunogold labeling. Ubiquitin and nucleoporins were identified as distinctively localizing components of the omega-shaped bleb structure. These findings suggest a functional link between the Torsin/cofactor system and NE/nuclear pore complex biogenesis or homeostasis and establish a Torsin-deficient cell line as a valuable experimental platform with which to decipher Torsin function.

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