scholarly journals Faculty Opinions recommendation of The short isoform of the host antiviral protein ZAP acts as an inhibitor of SARS-CoV-2 programmed ribosomal frameshifting.

Author(s):  
Jonathan Dinman
2021 ◽  
Author(s):  
Matthias Michael Zimmer ◽  
Anuja Nitin Kibe ◽  
Ulfert Rand ◽  
Lukas Pekarek ◽  
Luca Cicin-Sain ◽  
...  

Programmed ribosomal frameshifting (PRF) is a fundamental gene expression event in many viruses including SARS-CoV-2, which allows production of essential structural and replicative enzymes from an alternative reading frame. Despite the importance of PRF for the viral life cycle, it is still largely unknown how and to what extent cellular factors alter mechanical properties of frameshifting RNA molecules and thereby impact virulence. This prompted us to comprehensively dissect the interplay between the host proteome and the SARS-CoV-2 frameshift element. Here, we reveal that zinc-finger antiviral protein (ZAP-S) is a direct and specific regulator of PRF in SARS-CoV-2 infected cells. ZAP-S overexpression strongly impairs frameshifting and viral replication. Using in vitro ensemble and single-molecule techniques, we further demonstrate that ZAP-S directly interacts with the SARS-CoV-2 RNA and ribosomes and interferes with the folding of the frameshift RNA. Together these data illuminate ZAP-S as de novo host-encoded specific inhibitor of SARS-CoV-2 frameshifting and expand our understanding of RNA-based gene regulation.


1998 ◽  
Vol 72 (2) ◽  
pp. 1036-1042 ◽  
Author(s):  
Nilgun E. Tumer ◽  
Bijal A. Parikh ◽  
Ping Li ◽  
Jonathan D. Dinman

ABSTRACT Programmed ribosomal frameshifting is a molecular mechanism that is used by many RNA viruses to produce Gag-Pol fusion proteins. The efficiency of these frameshift events determines the ratio of viral Gag to Gag-Pol proteins available for viral particle morphogenesis, and changes in ribosomal frameshift efficiencies can severely inhibit virus propagation. Since ribosomal frameshifting occurs during the elongation phase of protein translation, it is reasonable to hypothesize that agents that affect the different steps in this process may also have an impact on programmed ribosomal frameshifting. We examined the molecular mechanisms governing programmed ribosomal frameshifting by using two viruses of the yeast Saccharomyces cerevisiae. Here, we present evidence that pokeweed antiviral protein (PAP), a single-chain ribosomal inhibitory protein that depurinates an adenine residue in the α-sarcin loop of 25S rRNA and inhibits translocation, specifically inhibits Ty1-directed +1 ribosomal frameshifting in intact yeast cells and in an in vitro assay system. Using an in vivo assay for Ty1 retrotransposition, we show that PAP specifically inhibits Ty1 retrotransposition, suggesting that Ty1 viral particle morphogenesis is inhibited in infected cells. PAP does not affect programmed −1 ribosomal frameshift efficiencies, nor does it have a noticeable impact on the ability of cells to maintain the M1-dependent killer virus phenotype, suggesting that −1 ribosomal frameshifting does not occur after the peptidyltransferase reaction. These results provide the first evidence that PAP has viral RNA-specific effects in vivo which may be responsible for the mechanism of its antiviral activity.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthias M. Zimmer ◽  
Anuja Kibe ◽  
Ulfert Rand ◽  
Lukas Pekarek ◽  
Liqing Ye ◽  
...  

AbstractProgrammed ribosomal frameshifting (PRF) is a fundamental gene expression event in many viruses, including SARS-CoV-2. It allows production of essential viral, structural and replicative enzymes that are encoded in an alternative reading frame. Despite the importance of PRF for the viral life cycle, it is still largely unknown how and to what extent cellular factors alter mechanical properties of frameshift elements and thereby impact virulence. This prompted us to comprehensively dissect the interplay between the SARS-CoV-2 frameshift element and the host proteome. We reveal that the short isoform of the zinc-finger antiviral protein (ZAP-S) is a direct regulator of PRF in SARS-CoV-2 infected cells. ZAP-S overexpression strongly impairs frameshifting and inhibits viral replication. Using in vitro ensemble and single-molecule techniques, we further demonstrate that ZAP-S directly interacts with the SARS-CoV-2 RNA and interferes with the folding of the frameshift RNA element. Together, these data identify ZAP-S as a host-encoded inhibitor of SARS-CoV-2 frameshifting and expand our understanding of RNA-based gene regulation.


2021 ◽  
Author(s):  
Matthias Zimmer ◽  
Anuja Kibe ◽  
Ulfert Rand ◽  
Lukas Pekarek ◽  
Luka Cicin-Sain ◽  
...  

Abstract Programmed ribosomal frameshifting (PRF) is a fundamental gene expression event in many viruses including SARS-CoV-2, which allows production of essential structural and replicative enzymes from an alternative reading frame. Despite the importance of PRF for the viral life cycle, it is still largely unknown how and to what extent cellular factors alter mechanical properties of frameshifting RNA molecules and thereby impact virulence. This prompted us to comprehensively dissect the interplay between the host proteome and the SARS-CoV-2 frameshift element. Here, we reveal that zinc-finger antiviral protein (ZAP-S) is a direct and specific regulator of PRF in SARS-CoV-2 infected cells. ZAP-S overexpression strongly impairs frameshifting and viral replication. Using in vitro ensemble and single-molecule techniques, we further demonstrate that ZAP-S directly interacts with the SARS-CoV-2 RNA and ribosomes and interferes with the folding of the frameshift RNA. Together these data illuminate ZAP-S as de novo host-encoded specific inhibitor of SARS-CoV-2 frameshifting and expand our understanding of RNA-based gene regulation.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1230
Author(s):  
Sawsan Napthine ◽  
Chris H. Hill ◽  
Holly C. M. Nugent ◽  
Ian Brierley

The product of the interferon-stimulated gene C19orf66, Shiftless (SHFL), restricts human immunodeficiency virus replication through downregulation of the efficiency of the viral gag/pol frameshifting signal. In this study, we demonstrate that bacterially expressed, purified SHFL can decrease the efficiency of programmed ribosomal frameshifting in vitro at a variety of sites, including the RNA pseudoknot-dependent signals of the coronaviruses IBV, SARS-CoV and SARS-CoV-2, and the protein-dependent stimulators of the cardioviruses EMCV and TMEV. SHFL also reduced the efficiency of stop-codon readthrough at the murine leukemia virus gag/pol signal. Using size-exclusion chromatography, we confirm the binding of the purified protein to mammalian ribosomes in vitro. Finally, through electrophoretic mobility shift assays and mutational analysis, we show that expressed SHFL has strong RNA binding activity that is necessary for full activity in the inhibition of frameshifting, but shows no clear specificity for stimulatory RNA structures.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joel M. J. Tan ◽  
Monica E. Garner ◽  
James M. Regeimbal ◽  
Catherine J. Greene ◽  
Jorge D. Rojas Márquez ◽  
...  

AbstractThe type I interferon (IFN) signaling pathway has important functions in resistance to viral infection, with the downstream induction of interferon stimulated genes (ISG) protecting the host from virus entry, replication and spread. Listeria monocytogenes (Lm), a facultative intracellular foodborne pathogen, can exploit the type I IFN response as part of their pathogenic strategy, but the molecular mechanisms involved remain unclear. Here we show that type I IFN suppresses the antibacterial activity of phagocytes to promote systemic Lm infection. Mechanistically, type I IFN suppresses phagosome maturation and proteolysis of Lm virulence factors ActA and LLO, thereby promoting phagosome escape and cell-to-cell spread; the antiviral protein, IFN-induced transmembrane protein 3 (IFITM3), is required for this type I IFN-mediated alteration. Ifitm3−/− mice are resistant to systemic infection by Lm, displaying decreased bacterial spread in tissues, and increased immune cell recruitment and pro-inflammatory cytokine signaling. Together, our findings show how an antiviral mechanism in phagocytes can be exploited by bacterial pathogens, and implicate IFITM3 as a potential antimicrobial therapeutic target.


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