Molecular basis of polyadenylated RNA fate determination in the nucleus - PubMed
3 hours ago
- #RNA export
- #RNA fate determination
- #Nuclear RNA decay
- The study investigates how cells determine the fate of polyadenylated (pA+) RNAs in the nucleus, distinguishing between export to the cytoplasm for functional RNAs and nuclear degradation for non-functional ones.
- The DExD-box ATPase UAP56 (DDX39B) is key in functional pA+ RNPs, aiding their docking to the nuclear pore complex via TREX-2, which promotes RNA export.
- The PAXT connection binds a TREX-2-like module (LENG8-PCID2-SEM1 trimer) that releases pA+ RNAs from UAP56, targeting them for decay by the nuclear exosome.
- The fate of pA+ RNPs is regulated by competing actions: nucleoplasmic PAXT (for decay) and nuclear pore complex-associated TREX-2 (for export), both interpreting UAP56-bound RNA as a signal.
- PAXT targets are typically short and intron-poor RNAs, leading to a model where sub-nuclear localization of PAXT and TREX-2 ensures degradation of short non-functional RNAs while allowing export of longer functional ones.