Coronavirus nucleocapsid protein
| Nucleocapsid protein | |||||||||
|---|---|---|---|---|---|---|---|---|---|
virion.[1] The N protein, contained entirely within the virion, is not visible.
● Blue: envelope ● Turquoise: spike glycoprotein (S) ● Red: envelope proteins (E) ● Green: membrane proteins (M) ● Orange: glycans | |||||||||
| Identifiers | |||||||||
| Symbol | CoV_nucleocap | ||||||||
| Pfam | PF00937 | ||||||||
| InterPro | IPR001218 | ||||||||
| |||||||||
The nucleocapsid (N) protein is a
History
COVID-19 was first identified in January 2020. A patient in the state of Washington was given a diagnosis of coronavirus infection on 20 January. A group of scientists based at the
Structure
The N protein is composed of two main
Both the
The C-terminal dimer has been structurally characterized by
Post-translational modifications
The N protein is post-translationally modified by phosphorylation at sites located in the IDR, particularly in the SR-rich region.[2][11] SARS-CoV-2 nucleocapsid (N) protein is arginine methylated by protein arginine methyltransferase 1 (PRMT1) at residues R95 and R177. Type I PRMT inhibitor (MS023) or substitution of R95 or R177 with lysine inhibited interaction of N protein with the 5’-UTR of SARS-CoV-2 genomic RNA, a property required for viral packaging | doi: 10.1016/j.jbc.2021.100821 | PMID 34029587. In several coronaviruses,
Expression and localization
The N protein is the most highly
N protein is localized primarily to the cytoplasm.[3] In many coronaviruses, a population of N protein is localized to the nucleolus,[3][4][15] thought to be associated with its effects on the cell cycle.[4]
Function
Genome packaging and viral assembly
The N protein binds to
Genomic and subgenomic RNA synthesis
Synthesis of genomic RNA appears to involve participation by the N protein. N is physically colocalized with the viral RNA-dependent RNA polymerase early in the replication cycle and forms interactions with non-structural protein 3, a component of the replicase-transcriptase complex.[3] Although N appears to facilitate efficient replication of genomic RNA, it is not required for RNA transcription in all coronaviruses.[3][17] In at least one coronavirus, transmissible gastroenteritis virus (TGEV), N is involved in template switching in the production of subgenomic mRNAs, a process that is a distinctive feature of viruses in the order Nidovirales.[3][17][18]
Cell cycle effects
Coronaviruses manipulate the
Immune system effects
The N protein is involved in
responses.Evolution and conservation
The sequences and structures of N proteins from different coronaviruses, particularly the C-terminal domains, appear to be well conserved.
Examination of SARS-CoV-2 sequences collected during the
The N protein's properties of being well conserved, not appearing to recombine frequently, and producing a strong T-cell response have led to it being studied as a potential target for coronavirus vaccines.[25][26][23][27] The vaccine candidate UB-612 is one such experimental vaccine that targets the N protein, along with other viral proteins, to attempt to induce broad immunity.[28][29]
References
- ^ Solodovnikov, Alexey; Arkhipova, Valeria (2021-07-29). "Достоверно красиво: как мы сделали 3D-модель SARS-CoV-2" [Truly beautiful: how we made the SARS-CoV-2 3D model] (in Russian). N+1. Archived from the original on 2021-07-30. Retrieved 30 July 2021.
- ^ PMID 24418573.
- ^ PMID 25105276.
- ^ PMID 33251267.
- PMID 33318065.
- PMID 32160149.
- ^ PMID 32654247.
- PMID 32849654.
- ^ PMID 26691874.
- ^ PMID 33264373.
- ^ PMID 32201497.
- PMID 29199039.
- PMID 34462738.
- PMID 34548480.
- PMID 16877062.
- PMID 32760062.
- ^ PMID 19955314.
- PMID 26958916.
- PMID 15681410.
- PMID 17108024.
- PMID 32295922.
- PMID 32953130.
- ^ PMID 34638137.
- PMID 32238584.
- PMID 32473127.
- PMID 32546606.
- S2CID 252283038.
- PMID 34322129.
- PMID 35316221.
