NXF1 and CRM1 nuclear export pathways orchestrate nuclear export, translation and packaging of murine leukaemia retrovirus unspliced RNA
Résumé
Cellular mRNAs are exported from the nucleus as fully spliced RNAs. Proofreading mechanisms eliminate
unprocessed and irregular pre-mRNAs to control the quality of gene expression. Retroviruses need to
export partially spliced and unspliced full-length RNAs to the cytoplasm where they serve as templates
for protein synthesis and/or as encapsidated RNA in progeny viruses. Genetically complex retroviruses
such as HIV-1 use Rev-equivalent proteins to export intron-retaining RNA from the nucleus using the
cellular CRM1-driven nuclear export machinery. By contrast, genetically simpler retroviruses such as
murine leukaemia virus (MLV) recruit the NXF1 RNA export machinery. In this study, we reveal for the
first time that MLV hijacks both NXF1 and CRM1-dependent pathways to achieve optimal replication
capacity. The CRM1-pathway marks the MLV full-length RNA (FL RNA) for packaging, while NXF1-driven
nuclear export is coupled to translation. Thus, the cytoplasmic function of the viral RNA is determined
early in the nucleus. Depending on the nature of ribonucleoprotein complex formed on FL RNA cargo in
the nucleus, the FL RNA will be addressed to the translation machinery sites or to the virus-assembly
sites at the plasma membrane.
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers produits par l'(les) auteur(s)
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