Biology subjects

Kubanska, M. A.

Publications and source records attributed to Kubanska, M. A..

2 recordsLinked to original sources

bioRxiv2026

How the TREX-2 complex associates with the nuclear pore

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 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 mRNP remodeling to NPC-facilitated transport.

cell biology↗

bioRxiv2024

The small GTPase Ran defines Nuclear Pore Complex asymmetry

Nuclear pore complexes (NPCs) bridge across the nuclear envelope and mediate nucleocytoplasmic exchange. They consist of hundreds of nucleoporin building blocks and exemplify the structural complexity of macromolecular assemblies. To ensure transport directionality, different nucleoporin complexes are attached to the cytosolic and nuclear face of the NPC. How those asymmetric structures are faithfully assembled onto the symmetric scaffold architecture that exposes the same interaction surfaces to either side, remained enigmatic. Here we combine cryo-electron tomography, subtomogram averaging, and template matching with live cell imaging to address this question in budding yeast and Drosophila melanogaster. We genetically induce ectopic nuclear pores and show that pores outside the nuclear envelope are symmetric. We furthermore demonstrate that the peripheral NPC configuration depends on the nucleotide state of the small GTPase Ran. Our findings indicate that the nuclear transport system is self-regulatory, namely the same molecular mechanism controls both transport and transport channel composition.

cell biology↗