ID   NCAP_I54A0              Reviewed;         498 AA.
AC   P31609;
DT   01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1993, sequence version 1.
DT   08-NOV-2023, entry version 81.
DE   RecName: Full=Nucleoprotein {ECO:0000255|HAMAP-Rule:MF_04070};
DE   AltName: Full=Nucleocapsid protein {ECO:0000255|HAMAP-Rule:MF_04070};
DE            Short=Protein N {ECO:0000255|HAMAP-Rule:MF_04070};
GN   Name=NP {ECO:0000255|HAMAP-Rule:MF_04070};
OS   Influenza A virus (strain A/Leningrad/1/1954 H1N1).
OC   Viruses; Riboviria; Orthornavirae; Negarnaviricota; Polyploviricotina;
OC   Insthoviricetes; Articulavirales; Orthomyxoviridae; Alphainfluenzavirus;
OC   Alphainfluenzavirus influenzae; Influenza A virus.
OX   NCBI_TaxID=393557;
OH   NCBI_TaxID=8782; Aves.
OH   NCBI_TaxID=9606; Homo sapiens (Human).
OH   NCBI_TaxID=9823; Sus scrofa (Pig).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX   PubMed=4038349;
RA   Beklemishev A.B., Blinov V.M., Vassilenko S.K., Golovin S.Y.,
RA   Karginov V.A., Mamayev L.V., Mikriukov N.N., Netesov S.V., Petrenko V.A.,
RA   Petrov N.A., Frolov I.V.;
RT   "Synthesis, cloning and determination of the primary structure of a full-
RT   size DNA copy of the NP protein gene from influenza virus type A.";
RL   Bioorg. Khim. 11:636-640(1985).
CC   -!- FUNCTION: Encapsidates the negative strand viral RNA, protecting it
CC       from nucleases. The encapsidated genomic RNA is termed the
CC       ribonucleoprotein (RNP) and serves as template for transcription and
CC       replication. The RNP needs to be localized in the host nucleus to start
CC       an infectious cycle, but is too large to diffuse through the nuclear
CC       pore complex. NP comprises at least 2 nuclear localization signals that
CC       are responsible for the active RNP import into the nucleus through
CC       cellular importin alpha/beta pathway. Later in the infection, nclear
CC       export of RNPs are mediated through viral proteins NEP interacting with
CC       M1 which binds nucleoproteins. It is possible that nucleoprotein binds
CC       directly host exportin-1/XPO1 and plays an active role in RNPs nuclear
CC       export. M1 interaction with RNP seems to hide nucleoprotein's nuclear
CC       localization signals. Soon after a virion infects a new cell, M1
CC       dissociates from the RNP under acidification of the virion driven by M2
CC       protein. Dissociation of M1 from RNP unmasks nucleoprotein's nuclear
CC       localization signals, targeting the RNP to the nucleus.
CC       {ECO:0000255|HAMAP-Rule:MF_04070}.
CC   -!- SUBUNIT: Homomultimerizes to form the nucleocapsid. May bind host
CC       exportin-1/XPO1. Binds to viral genomic RNA. Protein-RNA contacts are
CC       mediated by a combination of electrostatic interactions between
CC       positively charged residues and the phosphate backbone and planar
CC       interactions between aromatic side chains and bases.
CC       {ECO:0000255|HAMAP-Rule:MF_04070}.
CC   -!- SUBCELLULAR LOCATION: Virion {ECO:0000255|HAMAP-Rule:MF_04070}. Host
CC       nucleus {ECO:0000255|HAMAP-Rule:MF_04070}.
CC   -!- PTM: Late in virus-infected cells, may be cleaved from a 56-kDa protein
CC       to a 53-kDa protein by a cellular caspase. This cleavage might be a
CC       marker for the onset of apoptosis in infected cells or have a specific
CC       function in virus host interaction. {ECO:0000255|HAMAP-Rule:MF_04070}.
CC   -!- SIMILARITY: Belongs to the influenza viruses nucleoprotein family.
CC       {ECO:0000255|HAMAP-Rule:MF_04070}.
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DR   EMBL; M38279; AAA43459.1; -; Genomic_RNA.
DR   SMR; P31609; -.
DR   GO; GO:0019029; C:helical viral capsid; IEA:UniProtKB-UniRule.
DR   GO; GO:0042025; C:host cell nucleus; IEA:UniProtKB-SubCell.
DR   GO; GO:1990904; C:ribonucleoprotein complex; IEA:UniProtKB-KW.
DR   GO; GO:0019013; C:viral nucleocapsid; IEA:UniProtKB-UniRule.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0005198; F:structural molecule activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0046718; P:viral entry into host cell; IEA:UniProtKB-KW.
DR   GO; GO:0075732; P:viral penetration into host nucleus; IEA:UniProtKB-UniRule.
DR   HAMAP; MF_04070; INFV_NCAP; 1.
DR   InterPro; IPR002141; Flu_NP.
DR   Pfam; PF00506; Flu_NP; 1.
DR   SUPFAM; SSF161003; flu NP-like; 1.
PE   3: Inferred from homology;
KW   Capsid protein; Helical capsid protein; Host nucleus;
KW   Host-virus interaction; Ribonucleoprotein; RNA-binding;
KW   Viral nucleoprotein; Viral penetration into host nucleus; Virion;
KW   Virus entry into host cell.
FT   CHAIN           1..498
FT                   /note="Nucleoprotein"
FT                   /id="PRO_0000079071"
FT   REGION          1..21
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   MOTIF           1..18
FT                   /note="Unconventional nuclear localization signal"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_04070"
FT   MOTIF           198..216
FT                   /note="Bipartite nuclear localization signal"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_04070"
SQ   SEQUENCE   498 AA;  56169 MW;  CC44B44C0C8CB579 CRC64;
     MASQGTKRSY EQMETDGERQ NATEIRASVG KMIGGIGRFY IQMCTELKLS DYEGRLIQNS
     LTIERMVLSA FDERRNKYLE EHPSAGKDPK KTGGPIYRRV NGKWMRELIL YDKEEIRRIW
     RQANNGDDAT AGLTHMMIWH SNLNDATYQR TRALVRTGMD PRMCSLMQGS TLPRRSGAAG
     AAVKGVGTMV MELVRMIKRG INDRNFWRGE NGRKTRIAYE RMCNILKGKF QTAAQKAMMD
     QVRESRNPGN AEFEDLTFLA RSALILRGSV AHKSCLPACV YGPAVASGYD FEREGYSLVG
     IDPFRLLQNS QVYSLIRPNE NPAHKSQLVW MACHSAAFED LRVLSFIKGT KVLPRGKLST
     RGVQIASNEN METMESSTLE LRSRYWAIRT RSGGNTNQQR ASAGQISIQP TFSVQRNLPF
     DRTTVMAAFS GNTEGRTSDM RTEIIRMMES ARPEDVSFQG RGVFELSDEK AASPIVPSFD
     MSNEGSYFFG DNAEEYDN
//