TREX-2 acts as a stationary mRNA export receptor at the nuclear pore. — ASN Events
  1. Schedule
  2. Concurrent Session 8A: RNA Biology
  3. TREX-2 acts as a stationary mRNA export receptor at the nuclear pore.

TREX-2 acts as a stationary mRNA export receptor at the nuclear pore. (133178)

Yoona Kim 1 2 , Ashleigh Solano 3 4 , Katja Bendrin 5 , Elizabeth Hinde 3 , Tamas Fischer 2
  1. Biochemistry and Molecular biology department, Monash University, Clayton, VIC, Australia
  2. John Curtin School of Medical Research, The Australian National University, Acton, ACT, Australia
  3. School of Physics, The University of Melbourne, Melbourne, VIC, Australia
  4. Walter and Eliza Hall Institute (WEHI), Parkville, Victoria, Australia
  5. Biochemistry center, Heidelberg University, Heidelberg, Germany

In all eukaryotes, nuclear transport receptors mediate the translocation of macromolecules across the nuclear pore complex (NPC). Traditionally, mRNA export has been attributed solely to the Nxf1-p15 export receptor.  Paradoxically, in fission yeast the Nxf1-p15 pathway is dispensable for viability, suggesting the existence of a parallel export pathway. Here, we show that the NPC-anchored TREX-2 complex also functions as a bona fide mRNA export receptor. Mechanistically, the mRNA-binding head domain is connected to the NPC-anchored base by an exceptionally long linker. Importantly, the TREX-2 linker can traverse the entire NPC channel and deliver its cargo to the cytoplasm independently of Nxf1-p15. This lasso-like mechanism contrasts with all previously characterised transport receptors, which shuttle between nuclear and cytoplasmic compartments. Instead, TREX-2 provides a distinct, stationary mode of mRNA export. Our findings redefine TREX-2 as an export receptor and uncover a fundamentally new mechanism of nucleocytoplasmic transport.

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