Title : In vitro characterization of the SARS-CoV-2 nucleocapsid protein
Abstract:
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a positive-sense single-stranded RNA virus with a genome size of approximately 30 kilobases. The genome encodes non-structural proteins at its 5’ end and structural proteins at its 3’ end. Among the structural proteins, the nucleocapsid (N) protein is crucial for viral genome packaging and is highly expressed in infected cells. The N protein is known to interact with the viral genomic RNA to form a ribonucleoprotein (RNP) complex that plays a crucial role in viral RNA packaging.
The RNP complex is formed by the binding of multiple N protein molecules to the viral RNA, and this complex is then enclosed within the viral envelope to form the infectious virion. In addition to its role in nucleocapsid formation, we demonstrate that SARS-CoV-2 N protein exhibits RNA chaperone activity similar to the SARS-CoV N protein.
Our study shows that SARS-CoV-2 full-length N protein enhances RNA hybridization, and its C-terminal domain is sufficient to promote RNA annealing. We also observed that the N protein alters RNA structure, thereby contributing to RNA folding and functionality by displacing RNA chaperone activity. These findings provide insights into the multifunctional roles of SARS-CoV-2 N protein in viral replication and pathogenesis.
Audience Take Away:
- Understanding the structure and function of the nucleocapsid protein is critical for developing effective diagnostic and therapeutic tools against SARS-CoV-2 and potential following viruses.
- The study demonstrates that SARS-CoV-2 N exhibits RNA chaperone activity, which alters RNA structure and contributes to RNA folding and functionality. This information could be valuable in designing treatments that target the N protein and its effect on RNA function.
- We provide new information on the N protein’s role in viral genome packaging, which is crucial for the virus’ replication and survival, and understanding this process could help develop treatments that disrupt this step in the viral life cycle.
