REFERENCES: | 1) Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is an enveloped, single-stranded, positive-sense RNA virus that belongs to the Coronaviridae family 1. The SARS-CoV-2 genome, which shares 79.6% identity with SARS-CoV, encodes four essential structural proteins: the spike (S), envelope (E), membrane (M), and nucleocapsid protein (N) 2. The N protein is 46 kDa and consists of two highly conserved structural domains, the N-terminal domain (NTD) and C-terminal domain (CTD), connected by a linker region. The NTD and CTD are involved in RNA binding and self-oligomerization, respectively 3, 4. The primary function of the N protein is to bind to and package the viral RNA genome into a helical ribonucleoprotein complex 5. The N protein is also involved in other critical steps of the viral life cycle, including transcription, replication, and modulating infected cell signaling pathways 6, 7. The N protein is abundantly expressed during infection and is highly conserved, sharing 90% amino acid homology with the SARS-CoV N protein 8. It is also immunogenic, and antibodies 8,9 and memory T cells 10, 11 targeting the N protein are present in the sera of convalescent COVID-19 patients, identifying the N protein as a suitable candidate for vaccine development and diagnostic assays. Diagnostic assays based on the N protein effectively detect antibodies in the sera of patients infected with SARS-CoV-2 12. The N protein also contributes to immune evasion by antagonizing antiviral RNAi 13, suggesting its potential value as a targeted therapeutic. |
| 2) Zhou, P., Yang, X., Wang, X. et al. Nature 579, 270–273. 2020. | | 3) Wu, F., Zhao, S., Yu, B. et al. Nature 579, 265–269. 2020. | | 4) Kang S, Yang M, Hong Z, et al. Acta Pharm Sin B. 10.1016/j.apsb.2020.04.009. 2020. | | 5) Chang CK, Sue SC, Yu TH, et al. J Biomed Sci. 13(1):59-72. 2006. | | 6) Hsieh PK, Chang SC, Huang CC, et al. J Virol. 79(22):13848-13855. 2005. | | 7) Surjit M, Lal SK. Infect Genet Evol. 8(4):397-405. 2008. | | 8) Hurst KR, Ye R, Goebel SJ, Jayaraman P, Masters PS. J Virol. 84(19):10276-10288. 2010. | | 9) Guo L., Ren L., Yang S., et al. Clinical Infectious Diseases: an Official Publication of the Infectious Diseases Society of America. 2020. | | 10) To K.K., Tsang O.T., Leung W.S., et al. Lancet Infect. Dis. 2020. |