The etiologic agent of the Covid-19 pandemic is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The viral membrane of SARS-CoV-2 surrounds a helical nucleocapsid in which the viral genome is encapsulated by the nucleocapsid protein. The nucleocapsid protein of SARS-CoV-2 is produced at high levels within infected cells, enhances the efficiency of viral RNA transcription, and is essential for viral replication. Here, we show that RNA induces cooperative liquid–liquid phase separation of the SARS-CoV-2 nucleocapsid protein. In agreement with its ability to phase separate in vitro, we show that the protein associates in cells with stress granules, cytoplasmic RNA/protein granules that form through liquid-liquid phase separation and are modulated by viruses to maximize replication efficiency. Liquid–liquid phase separation generates high-density protein/RNA condensates that recruit the RNA-dependent RNA polymerase complex of SARS-CoV-2 providing a mechanism for efficient transcription of viral RNA. Inhibition of RNA-induced phase separation of the nucleocapsid protein by small molecules or biologics thus can interfere with a key step in the SARS-CoV-2 replication cycle. The SARS-CoV-2 viral genome is encapsulated by the nucleocapsid protein (N SARS-CoV-2 ) that is essential for viral replication. Here, the authors show that RNA induces liquid-liquid phase separation of N SARS-CoV-2 and how N SARS-CoV-2 phosphorylation modulates RNA-binding and phase separation and that these RNA/N SARS-CoV-2 -droplets recruit and concentrate the SARS-CoV-2 RNA-dependent RNA polymerase complex in vitro, which would enable high initiation and elongation rates during viral transcription.
【저자키워드】 structural biology, Intrinsically disordered proteins, Solution-state NMR, 【초록키워드】 viruses, SARS-CoV-2, coronavirus, pandemic, COVID-19 pandemic, Genome, Transcription, inhibition, in vitro, severe acute respiratory syndrome Coronavirus, virus, nucleocapsid protein, RNA, Replication, Protein, Viral, nucleocapsid, viral replication, Phosphorylation, RNA-dependent RNA polymerase, Small molecules, small molecule, SARS-CoV-2 RNA, Viral RNA, stress granules, respiratory, mechanism, viral genome, Efficiency, etiologic agent, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, infected cells, viral membrane, complex, viral transcription, replication efficiency, high-density, Cell, ENhance, SARS-CoV-2 viral, produced, generate, cytoplasmic, modulate, induce, interfere, modulated, Granule, recruit, the SARS-CoV-2, 【제목키워드】 SARS-CoV-2, Protein,