Characterization of SARS-CoV-2 nucleocapsid protein reveals multiple functional consequences of the C-terminal domain
Chao Wu,
Abraham J. Qavi,
Asmaa Hachim,
Niloufar Kavian,
Aidan R. Cole,
Austin B. Moyle,
Nicole D. Wagner,
Joyce Sweeney-Gibbons,
Henry W. Rohrs,
Michael L. Gross,
J. S. Malik Peiris,
Christopher F. Basler,
Christopher W. Farnsworth,
Sophie A. Valkenburg,
Gaya K. Amarasinghe,
Daisy W. Leung
Affiliations
Chao Wu
Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
Abraham J. Qavi
Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
Asmaa Hachim
HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
Niloufar Kavian
HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China; Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Assistance Publique–Hôpitaux de Paris, Hôpital Universitaire Paris Centre, Centre Hospitalier Universitaire Cochin, Service d’Immunologie Biologique, Paris, France; Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
Aidan R. Cole
Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
Austin B. Moyle
Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
Nicole D. Wagner
Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
Joyce Sweeney-Gibbons
Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
Henry W. Rohrs
Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
Michael L. Gross
Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
J. S. Malik Peiris
HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China; Division of Public Health Laboratory Sciences, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
Christopher F. Basler
Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
Christopher W. Farnsworth
Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; Corresponding author
Sophie A. Valkenburg
HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China; Corresponding author
Gaya K. Amarasinghe
Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; Corresponding author
Daisy W. Leung
Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; Corresponding author
Summary: Nucleocapsid (N) encoded by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays key roles in the replication cycle and is a critical serological marker. Here, we characterize essential biochemical properties of N and describe the utility of these insights in serological studies. We define N domains important for oligomerization and RNA binding and show that N oligomerization provides a high-affinity RNA-binding platform. We also map the RNA-binding interface, showing protection in the N-terminal domain and linker region. In addition, phosphorylation causes reduction of RNA binding and redistribution of N from liquid droplets to loose coils, showing how N-RNA accessibility and assembly may be regulated by phosphorylation. Finally, we find that the C-terminal domain of N is the most immunogenic, based on antibody binding to patient samples. Together, we provide a biochemical description of SARS-CoV-2 N and highlight the value of using N domains as highly specific and sensitive diagnostic markers.
