Principles of RNA recruitment to viral ribonucleoprotein condensates in a segmented dsRNA virus
- Max Planck Institute of Biochemistry, Germany
- University of Cambridge, United Kingdom
- MRC Laboratory of Molecular Biology, United Kingdom
Abstract
Rotaviruses transcribe eleven distinct RNAs that must be co-packaged prior to their replication to make an infectious virion. During infection, nontranslating rotavirus transcripts accumulate in cytoplasmic protein-RNA granules known as viroplasms that support segmented genome assembly and replication via a poorly understood mechanism. Here we analysed the RV transcriptome by combining DNA-barcoded smFISH of rotavirus-infected cells. Rotavirus RNA stoichiometry in viroplasms appears to be distinct from the cytoplasmic transcript distribution, with the largest transcript being the most enriched in viroplasms, suggesting a selective RNA enrichment mechanism. While all eleven types of transcripts accumulate in viroplasms, their stoichiometry significantly varied between individual viroplasms. Accumulation of transcripts requires the presence of 3' untranslated terminal regions and viroplasmic localisation of the viral polymerase VP1, consistent with the observed lack of polyadenylated transcripts in viroplasms. Our observations reveal similarities between viroplasms and other cytoplasmic RNP granules and identify viroplasmic proteins as drivers of viral RNA assembly during viroplasm formation.
Data availability
RNA-Seq data have been uploaded, and the SRA Illumina reads data are available under the accession number PRJNA702157 (SRR13723918, RNA-Seq of Bovine Rotavirus A: Strain RF).SRA Metadata:BioProject: PRJNA702157 (Bovine rotavirus strain RF transcriptome of MA104 cells)BioSample: SAMN17926863 (Viral sample from Bovine rotavirus A)SRA: SRR13723918 (RNA-Seq of Bovine Rotavirus A: Strain RF)All data generated during this study are included in the manuscript and supporting files. Source data files have been provided for all figures.
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Bovine rotavirus strain RF transcriptome of MA104 cellsNCBI BioProject, PRJNA702157.
Article and author information
Author details
Alexander Borodavka
Funding
Wellcome Trust (213437/Z/18/Z)
- Alexander Borodavka
Deutsche Forschungsgemeinschaft (SFB1032)
- Ralf Jungmann
European Research Council (MolMap 680241)
- Ralf Jungmann
Max Planck Institute for Biochemistry
- Sebastian Strauss
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2023, Strauss et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Principles of RNA recruitment to viral ribonucleoprotein condensates in a segmented dsRNA virus
eLife 12:e68670.
https://doi.org/10.7554/eLife.68670
Further reading
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- Biochemistry and Chemical Biology
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Teichoic acids (TA) are linear phospho-saccharidic polymers and important constituents of the cell envelope of Gram-positive bacteria, either bound to the peptidoglycan as wall teichoic acids (WTA) or to the membrane as lipoteichoic acids (LTA). The composition of TA varies greatly but the presence of both WTA and LTA is highly conserved, hinting at an underlying fundamental function that is distinct from their specific roles in diverse organisms. We report the observation of a periplasmic space in Streptococcus pneumoniae by cryo-electron microscopy of vitreous sections. The thickness and appearance of this region change upon deletion of genes involved in the attachment of TA, supporting their role in the maintenance of a periplasmic space in Gram-positive bacteria as a possible universal function. Consequences of these mutations were further examined by super-resolved microscopy, following metabolic labeling and fluorophore coupling by click chemistry. This novel labeling method also enabled in-gel analysis of cell fractions. With this approach, we were able to titrate the actual amount of TA per cell and to determine the ratio of WTA to LTA. In addition, we followed the change of TA length during growth phases, and discovered that a mutant devoid of LTA accumulates the membrane-bound polymerized TA precursor.
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