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Annotation rule MF_04070
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General rule information [?]

Accession MF_04070
Dates 13-APR-2017 (Created)
20-NOV-2019 (Last updated, Version 4)
Viruses; Orthomyxoviridae
Template P03466 (NCAP_I34A1)

Propagated annotation [?]

Identifier, protein and gene names [?]

Protein name
RecName: Full=Nucleoprotein;
AltName: Full=Nucleocapsid protein;
Short=Protein N;
Gene name

Comments [?]

Function Encapsidates the negative strand viral RNA, protecting it from nucleases. The encapsidated genomic RNA is termed the ribonucleoprotein (RNP) and serves as template for transcription and replication. The RNP needs to be localized in the host nucleus to start an infectious cycle, but is too large to diffuse through the nuclear pore complex. NP comprises at least 2 nuclear localization signals that are responsible for the active RNP import into the nucleus through cellular importin alpha/beta pathway. Later in the infection, nclear export of RNPs are mediated through viral proteins NEP interacting with M1 which binds nucleoproteins. It is possible that nucleoprotein binds directly host exportin-1/XPO1 and plays an active role in RNPs nuclear export. M1 interaction with RNP seems to hide nucleoprotein's nuclear localization signals. Soon after a virion infects a new cell, M1 dissociates from the RNP under acidification of the virion driven by M2 protein. Dissociation of M1 from RNP unmasks nucleoprotein's nuclear localization signals, targeting the RNP to the nucleus.
Subunit Homomultimerizes to form the nucleocapsid. May bind host exportin-1/XPO1. Binds to viral genomic RNA. Protein-RNA contacts are mediated by a combination of electrostatic interactions between positively charged residues and the phosphate backbone and planar interactions between aromatic side chains and bases.
Subcellular location Virion. Host nucleus.
Ptm Late in virus-infected cells, may be cleaved from a 56-kDa protein to a 53-kDa protein by a cellular caspase. This cleavage might be a marker for the onset of apoptosis in infected cells or have a specific function in virus host interaction.
Similarity Belongs to the influenza viruses nucleoprotein family.

Keywords [?]

Gene Ontology [?]

GO:0019029; Cellular component: helical viral capsid.
GO:0042025; Cellular component: host cell nucleus.
GO:0019013; Cellular component: viral nucleocapsid.
GO:0003723; Molecular function: RNA binding.
GO:0005198; Molecular function: structural molecule activity.
GO:0075732; Biological process: viral penetration into host nucleus.

Cross-references [?]

Pfam PF00506; Flu_NP; 1;

Features [?]

case <OC:Alphainfluenzavirus>
From: NCAP_I34A1 (P03466)
Key     From     To       Description   Tag   Condition   FTGroup
MOTIF     1     18       Unconventional nuclear localization signal        
MOTIF     198     216       Bipartite nuclear localization signal        
end case

Additional information [?]

Size range 498-565 amino acids
Related rules None
Fusion None