SARS-CoV-2 Nsp14 mediates the effects of viral infection on the host cell transcriptome

Abstract

Viral infection involves complex set of events orchestrated by multiple viral proteins. To identify functions of SARS-CoV-2 proteins, we performed transcriptomic analyses of cells expressing individual viral proteins. Expression of Nsp14, a protein involved in viral RNA replication, provoked a dramatic remodeling of the transcriptome that strongly resembled that observed following SARS-CoV-2 infection. Moreover, Nsp14 expression altered the splicing of more than 1,000 genes and resulted in a dramatic increase in the number of circRNAs, which are linked to innate immunity. These effects were independent of the Nsp14 exonuclease activity and required the N7-guanine-methyltransferase domain of the protein. Activation of the NFkB pathway and increased expression of CXCL8 occurred early upon Nsp14 expression. We identified IMPDH2, which catalyzes the rate-limiting step of guanine nucleotides biosynthesis, as a key mediator of these effects. Nsp14 expression caused an increase in GTP cellular levels, and the effect of Nsp14 was strongly decreased in presence of IMPDH2 inhibitors. Together, our data demonstrate an unknown role for Nsp14 with implications for therapy.

Data availability

1.RNAseq data generated in this study is in GEO (GSE179251).2.RNA seq data already published and re-analyzed in this study are the following:-Sun, G., Cui, Q., Garcia, G. et al. Comparative transcriptomic analysis of SARS-CoV-2 infected cell model systems reveals differential innate immune responses. Sci Rep 11, 17146 (2021). https://doi.org/10.1038/s41598-021-96462-w, GSE169158-Blanco-Melo D, Nilsson-Payant BE, Liu WC, Uhl S, Hoagland D, Møller R, Jordan TX, Oishi K, Panis M, Sachs D, Wang TT, Schwartz RE, Lim JK, Albrecht RA, tenOever BR. Imbalanced Host Response to SARS-CoV-2 Drives Development of COVID-19. Cell. 2020 May 28;181(5):1036-1045.e9. doi: 10.1016/j.cell.2020.04.026. Epub 2020 May 15. PMID: 32416070; PMCID: PMC7227586, GSE147507All data generated or analyzed during this study are included in the manuscript and supporting files.

The following data sets were generated
The following previously published data sets were used

Article and author information

Author details

  1. Michela Zaffagni

    Department of Biology, Brandeis University, Waltham, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Jenna M Harris

    Department of Biology, Brandeis University, Waltham, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Ines L Patop

    Department of Biology, Brandeis University, Waltham, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Nagarjuna Reddy Pamudurti

    Department of Biology, Brandeis University, Waltham, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Sinead Nguyen

    Department of Biology, Brandeis University, Waltham, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Sebastian Kadener

    Department of Biology, Brandeis University, Waltham, United States
    For correspondence
    skadener@brandeis.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0080-5987

Funding

there is no external funding for this project

Reviewing Editor

  1. Kevin Struhl, Harvard Medical School, United States

Publication history

  1. Preprint posted: July 4, 2021 (view preprint)
  2. Received: July 5, 2021
  3. Accepted: March 10, 2022
  4. Accepted Manuscript published: March 16, 2022 (version 1)
  5. Version of Record published: April 29, 2022 (version 2)

Copyright

© 2022, Zaffagni 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.

Metrics

  • 1,433
    Page views
  • 318
    Downloads
  • 2
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Michela Zaffagni
  2. Jenna M Harris
  3. Ines L Patop
  4. Nagarjuna Reddy Pamudurti
  5. Sinead Nguyen
  6. Sebastian Kadener
(2022)
SARS-CoV-2 Nsp14 mediates the effects of viral infection on the host cell transcriptome
eLife 11:e71945.
https://doi.org/10.7554/eLife.71945
  1. Further reading

Further reading

    1. Chromosomes and Gene Expression
    2. Genetics and Genomics
    Joseph V Geisberg, Zarmik Moqtaderi ... Kevin Struhl
    Research Advance

    Alternative polyadenylation yields many mRNA isoforms whose 3' termini occur disproportionately in clusters within 3' UTRs. Previously, we showed that profiles of poly(A) site usage are regulated by the rate of transcriptional elongation by RNA polymerase (Pol) II (Geisberg et., 2020). Pol II derivatives with slow elongation rates confer an upstream-shifted poly(A) profile, whereas fast Pol II strains confer a downstream-shifted poly(A) profile. Within yeast isoform clusters, these shifts occur steadily from one isoform to the next across nucleotide distances. In contrast, the shift between clusters from the last isoform of one cluster to the first isoform of the next - is much less pronounced, even over large distances. GC content in a region 13-30 nt downstream from isoform clusters correlates with their sensitivity to Pol II elongation rate. In human cells, the upstream shift caused by a slow Pol II mutant also occurs continuously at the nucleotide level within clusters, but not between them. Pol II occupancy increases just downstream of the most speed-sensitive poly(A) sites, suggesting a linkage between reduced elongation rate and cluster formation. These observations suggest that 1) Pol II elongation speed affects the nucleotide-level dwell time allowing polyadenylation to occur, 2) poly(A) site clusters are linked to the local elongation rate and hence do not arise simply by intrinsically imprecise cleavage and polyadenylation of the RNA substrate, 3) DNA sequence elements can affect Pol II elongation and poly(A) profiles, and 4) the cleavage/polyadenylation and Pol II elongation complexes are spatially, and perhaps physically, coupled so that polyadenylation occurs rapidly upon emergence of the nascent RNA from the Pol II elongation complex.

    1. Biochemistry and Chemical Biology
    2. Chromosomes and Gene Expression
    Radhika A Varier, Theodora Sideri ... Folkert Jacobus van Werven
    Research Article

    N6-methyladenosine (m6A) RNA modification impacts mRNA fate primarily via reader proteins, which dictate processes in development, stress, and disease. Yet little is known about m6A function in Saccharomyces cerevisiae, which occurs solely during early meiosis. Here we perform a multifaceted analysis of the m6A reader protein Pho92/Mrb1. Cross-linking immunoprecipitation analysis reveals that Pho92 associates with the 3’end of meiotic mRNAs in both an m6A-dependent and independent manner. Within cells, Pho92 transitions from the nucleus to the cytoplasm, and associates with translating ribosomes. In the nucleus Pho92 associates with target loci through its interaction with transcriptional elongator Paf1C. Functionally, we show that Pho92 promotes and links protein synthesis to mRNA decay. As such, the Pho92-mediated m6A-mRNA decay is contingent on active translation and the CCR4-NOT complex. We propose that the m6A reader Pho92 is loaded co-transcriptionally to facilitate protein synthesis and subsequent decay of m6A modified transcripts, and thereby promotes meiosis.