tetano
Editor, Senior Moderator
Cell Rep
. 2021 Mar 12;108916.
doi: 10.1016/j.celrep.2021.108916. Online ahead of print.
Sarbecovirus ORF6 proteins hamper induction of interferon signaling
Izumi Kimura[SUP] 1 [/SUP], Yoriyuki Konno[SUP] 1 [/SUP], Keiya Uriu[SUP] 2 [/SUP], Kristina Hopfensperger[SUP] 3 [/SUP], Daniel Sauter[SUP] 3 [/SUP], So Nakagawa[SUP] 4 [/SUP], Kei Sato[SUP] 5 [/SUP]
Affiliations
Abstract
The presence of an ORF6 gene distinguishes sarbecoviruses such as severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 from other betacoronaviruses. Here we show that ORF6 inhibits induction of innate immune signaling, including upregulation of type I interferon (IFN) upon viral infection as well as type I and III IFN signaling. Intriguingly, ORF6 proteins from SARS-CoV-2 lineages are more efficient antagonists of innate immunity than their orthologs from SARS-CoV lineages. Mutational analyses identified residues E46 and Q56 as important determinants of the antagonistic activity of SARS-CoV-2 ORF6. Moreover, we show that the anti-innate immune activity of ORF6 depends on its C-terminal region and that ORF6 inhibits nuclear translocation of IRF3. Finally, we identify naturally occurring frameshift/nonsense mutations that result in an inactivating truncation of ORF6 in approximately 0.2% of SARS-CoV-2 isolates. Our findings suggest that ORF6 contributes to the poor IFN activation observed in individuals with coronavirus disease 2019 (COVID-19).
Keywords: COVID-19; ORF6; SARS-CoV-2; interferon-stimulated gene; type I interferon; type III interferon.
. 2021 Mar 12;108916.
doi: 10.1016/j.celrep.2021.108916. Online ahead of print.
Sarbecovirus ORF6 proteins hamper induction of interferon signaling
Izumi Kimura[SUP] 1 [/SUP], Yoriyuki Konno[SUP] 1 [/SUP], Keiya Uriu[SUP] 2 [/SUP], Kristina Hopfensperger[SUP] 3 [/SUP], Daniel Sauter[SUP] 3 [/SUP], So Nakagawa[SUP] 4 [/SUP], Kei Sato[SUP] 5 [/SUP]
Affiliations
- PMID: 33765414
- DOI: 10.1016/j.celrep.2021.108916
Abstract
The presence of an ORF6 gene distinguishes sarbecoviruses such as severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 from other betacoronaviruses. Here we show that ORF6 inhibits induction of innate immune signaling, including upregulation of type I interferon (IFN) upon viral infection as well as type I and III IFN signaling. Intriguingly, ORF6 proteins from SARS-CoV-2 lineages are more efficient antagonists of innate immunity than their orthologs from SARS-CoV lineages. Mutational analyses identified residues E46 and Q56 as important determinants of the antagonistic activity of SARS-CoV-2 ORF6. Moreover, we show that the anti-innate immune activity of ORF6 depends on its C-terminal region and that ORF6 inhibits nuclear translocation of IRF3. Finally, we identify naturally occurring frameshift/nonsense mutations that result in an inactivating truncation of ORF6 in approximately 0.2% of SARS-CoV-2 isolates. Our findings suggest that ORF6 contributes to the poor IFN activation observed in individuals with coronavirus disease 2019 (COVID-19).
Keywords: COVID-19; ORF6; SARS-CoV-2; interferon-stimulated gene; type I interferon; type III interferon.