• SARS-CoV-2-encoded Nucleocapsid Protein Acts as a Viral Suppressor of RNA interference in Cells

    Subjects: Biology >> Virology submitted time 2020-02-22

    Abstract: The SARS-CoV-2 outbreak has emerged and is still ongoing in Wuhan and other areas of China and world. Human infections by SARS-CoV-2 lead to diseases ranging from mild symptoms to severe pneumonia and even death. And in the current situation, better understanding of the virology and virus-host interactions of SARS-CoV-2 would be vital for the efforts to control the infections and develop effective therapies. RNA interference (RNAi) is an evolutionarily conserved antiviral immune mechanism in diverse eukaryotic organisms, and numerous viruses have been found to encode their own viral suppressors of RNAi (VSRs) as countermeasures. In this study, we uncovered that the nucleocapsid (N) protein encoded by SARS-CoV-2 effectively suppressed RNAi triggered by either small hairpin RNAs (shRNAs) or small interfering RNAs (siRNAs) in cultured human cells. Furthermore, similar with VSRs encoded by other viruses, SARS-CoV-2 N protein shows double-stranded RNA (dsRNA)-binding activity, as it interacted with in vitro transcribed dsRNAs in human cells. Taken together, our findings showed that SARS-CoV-2 N exhibits the VSR activity in human cells, which could be as a key immune evasion factor for SARS-CoV-2 and contribute to its pathogenicity. "