Related Experiment Video
Updated: Oct 25, 2025
Large-scale Production of Recombinant RNAs on a Circular Scaffold Using a Viroid-derived System in Escherichia coli
Published on: November 30, 2018
Nuclear export of plant pararetrovirus mRNAs involves the TREX complex, two viral proteins and the highly structured
Julie Kubina1, Angèle Geldreich1, Jón Pol Gales1
1Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France.
Abstract:
In eukaryotes, the major nuclear export pathway for mature mRNAs uses the dimeric receptor TAP/p15, which is recruited to mRNAs via the multisubunit TREX complex, comprising the THO core and different export adaptors. Viruses that replicate in the nucleus adopt different strategies to hijack cellular export factors and achieve cytoplasmic translation of their mRNAs. No export receptors are known in plants, but Arabidopsis TREX resembles the mammalian complex, with a conserved hexameric THO core associated with ALY and UIEF proteins, as well as UAP56 and MOS11. The latter protein is an orthologue of mammalian CIP29. The nuclear export mechanism for viral mRNAs has not been described in plants. To understand this process, we investigated the export of mRNAs of the pararetrovirus CaMV in Arabidopsis and demonstrated that it is inhibited in plants deficient in ALY, MOS11 and/or TEX1. Deficiency for these factors renders plants partially resistant to CaMV infection. Two CaMV proteins, the coat protein P4 and reverse transcriptase P5, are important for nuclear export. P4 and P5 interact and co-localise in the nucleus with the cellular export factor MOS11. The highly structured 5' leader region of 35S RNAs was identified as an export enhancing element that interacts with ALY1, ALY3 and MOS11 in vitro.
Insights
Plant viruses hijack cellular export pathways. This study reveals that the export of Caulimovirus (CaMV) mRNAs in Arabidopsis depends on host factors ALY, MOS11, and TEX1, offering resistance to infection.
Area of Science:
- Plant virology
- Molecular biology
- Cellular export mechanisms
Background:
- Eukaryotic mRNA export relies on the TAP/p15 receptor and TREX complex.
- Plant nuclear export pathways and viral mRNA export mechanisms remain largely uncharacterized.
- Arabidopsis TREX complex shares similarities with mammalian counterparts, including MOS11, an orthologue of CIP29.
Purpose of the Study:
- To elucidate the nuclear export mechanism of viral mRNAs in plants.
- To investigate the role of cellular export factors in Caulimovirus (CaMV) infection.
- To identify viral and cellular components involved in plant viral mRNA export.
Main Methods:
- Investigated CaMV mRNA export in Arabidopsis mutants deficient in export factors (ALY, MOS11, TEX1).
- Assessed plant resistance to CaMV infection in these mutant lines.
- Analyzed interactions between CaMV proteins (P4, P5) and cellular factors (MOS11) using co-localization and interaction studies.
- Identified RNA elements (35S RNA 5' leader) involved in export via in vitro interaction assays with ALY1, ALY3, and MOS11.
Main Results:
- CaMV mRNA export is inhibited in Arabidopsis plants lacking ALY, MOS11, and/or TEX1.
- Deficiency in these export factors confers partial resistance to CaMV infection.
- CaMV proteins P4 and P5 are crucial for nuclear export and interact with MOS11.
- The 35S RNA 5' leader acts as an export-enhancing element interacting with ALY proteins and MOS11.
Conclusions:
- Plant viral mRNA export is mediated by host cellular export factors, specifically ALY, MOS11, and TEX1.
- CaMV utilizes its proteins P4 and P5 to interact with MOS11 for efficient nuclear export.
- The 5' leader region of CaMV RNA plays a critical role in facilitating its own export.
- Targeting these host-viral interactions could be a strategy for developing virus resistance in plants.
More Related Videos
Related Concept Videos
01:42Nuclear Export
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
02:31Nuclear Export of mRNA
02:31Nuclear Export of mRNA
02:22Regulated mRNA Transport
02:22Regulated mRNA Transport
01:34Nuclear Protein Sorting
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...