Your browser doesn't support javascript.
SARS-CoV-2 ORF6 Disrupts Bidirectional Nucleocytoplasmic Transport through Interactions with Rae1 and Nup98.
Addetia, Amin; Lieberman, Nicole A P; Phung, Quynh; Hsiang, Tien-Ying; Xie, Hong; Roychoudhury, Pavitra; Shrestha, Lasata; Loprieno, Michelle A; Huang, Meei-Li; Gale, Michael; Jerome, Keith R; Greninger, Alexander L.
  • Addetia A; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA.
  • Lieberman NAP; Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington, USA.
  • Phung Q; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA.
  • Hsiang TY; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA.
  • Xie H; Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA.
  • Roychoudhury P; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA.
  • Shrestha L; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA.
  • Loprieno MA; Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA.
  • Huang ML; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA.
  • Gale M; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA.
  • Jerome KR; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA.
  • Greninger AL; Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA.
mBio ; 12(2)2021 04 13.
Article in English | MEDLINE | ID: covidwho-1183285
ABSTRACT
RNA viruses that replicate in the cytoplasm often disrupt nucleocytoplasmic transport to preferentially translate their own transcripts and prevent host antiviral responses. The Sarbecovirus accessory protein ORF6 has previously been shown to be a major inhibitor of interferon production in both severe acute respiratory syndrome coronavirus (SARS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we show SARS-CoV-2-infected cells display an elevated level of nuclear mRNA accumulation compared to mock-infected cells. We demonstrate that ORF6 is responsible for this nuclear imprisonment of host mRNA, and using a cotransfected reporter assay, we show this nuclear retention of mRNA blocks expression of newly transcribed mRNAs. ORF6's nuclear entrapment of host mRNA is associated with its ability to copurify with the mRNA export factors, Rae1 and Nup98. These protein-protein interactions map to the C terminus of ORF6 and can be abolished by a single amino acid mutation in Met58. Overexpression of Rae1 restores reporter expression in the presence of SARS-CoV-2 ORF6. SARS-CoV ORF6 also interacts with Rae1 and Nup98. However, SARS-CoV-2 ORF6 more strongly copurifies with Rae1 and Nup98 and results in significantly reduced expression of reporter proteins compared to SARS-CoV ORF6, a potential mechanism for the delayed symptom onset and presymptomatic transmission uniquely associated with the SARS-CoV-2 pandemic. We also show that both SARS-CoV and SARS-CoV-2 ORF6 block nuclear import of a broad range of host proteins. Together, these data support a model in which ORF6 clogs the nuclear pore through its interactions with Rae1 and Nup98 to prevent both nuclear import and export, rendering host cells incapable of responding to SARS-CoV-2 infection.IMPORTANCE SARS-CoV-2, the causative agent of coronavirus disease 2019 (COVID-19), is an RNA virus with a large genome that encodes multiple accessory proteins. While these accessory proteins are not required for growth in vitro, they can contribute to the pathogenicity of the virus. We demonstrate that SARS-CoV-2-infected cells accumulate poly(A) mRNA in the nucleus, which is attributed to the accessory protein ORF6. Nuclear entrapment of mRNA and reduced expression of newly transcribed reporter proteins are associated with ORF6's interactions with the mRNA export proteins Rae1 and Nup98. SARS-CoV ORF6 also shows the same interactions with Rae1 and Nup98. However, SARS-CoV-2 ORF6 more strongly represses reporter expression and copurifies with Rae1 and Nup98 compared to SARS-CoV ORF6. Both SARS-CoV ORF6 and SARS-CoV-2 ORF6 block nuclear import of a wide range of host factors through interactions with Rae1 and Nup98. Together, our results suggest ORF6's disruption of nucleocytoplasmic transport prevents infected cells from responding to the invading virus.
Subject(s)
Keywords

Full text: Available Collection: International databases Database: MEDLINE Main subject: Viral Proteins / Cell Nucleus / Nucleocytoplasmic Transport Proteins / Nuclear Pore Complex Proteins / Nuclear Matrix-Associated Proteins / SARS-CoV-2 Limits: Humans Language: English Year: 2021 Document Type: Article Affiliation country: MBio.00065-21

Similar

MEDLINE

...
LILACS

LIS


Full text: Available Collection: International databases Database: MEDLINE Main subject: Viral Proteins / Cell Nucleus / Nucleocytoplasmic Transport Proteins / Nuclear Pore Complex Proteins / Nuclear Matrix-Associated Proteins / SARS-CoV-2 Limits: Humans Language: English Year: 2021 Document Type: Article Affiliation country: MBio.00065-21