9UPC

Structure of human TREX-2

Summary for 9UPC

• Entry DOI: 10.2210/pdb9upc/pdb
• Related: 9UPB
• EMDB information: 64391
• Descriptor: Germinal-center associated nuclear protein, PCI domain-containing protein 2, 26S proteasome complex subunit SEM1 (3 entities in total)
• Functional Keywords: mrna nuclear export, trex-2, uap56, gene regulation
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 3
• Total formula weight: 109348.27

Authors

Zhang, X.,Gong, X.,Ge, X. (deposition date: 2025-04-28, release date: 2026-02-11, Last modification date: 2026-07-01)

Primary citation

Gong, X.,Tao, R.,Ge, X.,Zhu, H.,Li, M.,Chen, Y.,Gao, Y.,Hang, J.,Zhang, X.
Molecular insights into mRNA export regulation by the human TREX-2 complex.
Nat Commun, 17:-, 2026

PubMed Abstract: The nuclear export of mRNA represents a critical regulatory node in eukaryotic gene expression. This process is orchestrated by two conserved multi-subunit assemblies: the transcription-and-export complex (TREX) and TREX-2. While TREX facilitates mRNP packaging through multivalent RNA-protein interactions, the precise mechanism by which TREX-2 contributes to mRNA export has remained elusive. Here, we report a functional interaction between UAP56 and TREX-2 and resolve the structures of TREX-2 in both apo and UAP56-bound states. UAP56 engages TREX-2 via its N-terminal region, positioning its RecA domains on the V-shaped surface of the complex. A conserved loop from TREX-2 inserts between the RecA domains of UAP56, stabilizing an open conformation. Biochemical assays demonstrate that TREX-2 significantly stimulates the ATPase activity of UAP56, thereby promoting RNA release. These findings provide structural and mechanistic insights into TREX-2-mediated regulation of mRNA export through UAP56 remodeling.

PubMed: 41748650
DOI: 10.1038/s41467-026-70088-w

Experimental method

ELECTRON MICROSCOPY (3.14 Å)