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Updated: Oct 28, 2026

Single-Molecule Imaging of Nuclear Transport
Published on: June 9, 2010
How the TREX-2 complex associates with the nuclear pore
Agnieszka Obarska-Kosinska1, Ying Zhu2, Katharina Geißler3
1Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany; European Molecular Biology Laboratory Hamburg, Notkestraße 85, 22607 Hamburg, Germany.
Abstract:
Nuclear pore complexes (NPCs) control nucleocytoplasmic transport in eukaryotes, yet their architecture remains incompletely understood. Here, we report a substantially extended structure of the human NPC, obtained by combining cryo-electron tomography, crosslinking mass spectrometry, and AI-assisted integrative modeling. We resolve the molecular arrangement of translocated promoter region (TPR), NUP153, NUP50, and ZC3HC1 and reveal that five additional proteins-TMEM209, SMPD4, GANP, Centrin-2, and ENY2-are incorporated into the NPC. Unexpectedly, GANP, Centrin-2, and ENY2, core members of the TREX-2 mRNA export complex, are built into the nuclear ring. This finding establishes TREX-2 not as a transiently associated factor, but as an integral NPC module, positioning it opposite of the cytoplasmic NUP214 mRNA export platform. Together, our results redefine the molecular composition of the inner ring, nuclear ring, and nuclear basket. They suggest a direct structural basis that couples TREX-2-mediated messenger ribonucleoprotein particle (mRNP) remodeling to NPC-facilitated transport.
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