Nucleocapsid protein is a most abundant protein of coronavirus on the helical nucleocapsid of coronaviruses. N protein of SARS CoV-2 is a structural protein required for RNA synthesis, and has RNA chaperone activity that may be involved in template switch. N protein enters the host cell with the viral RNA to facilitate its replication and process the virus particle assembly and release. N protein is a highly immunogenic phosphoprotein also implicated in modulating cell signalling pathways. Coronavirus nucleocapsid proteins localize to the cytoplasm and the nucleolus, a subnuclear structure, in both virus-infected primary cells and in cells transfected with plasmids that express N protein.