ID   NCAP_I73A2              Reviewed;         498 AA.
AC   Q07531;
DT   01-FEB-1995, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1995, sequence version 1.
DT   02-JUN-2021, entry version 76.
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/Memphis/4/1973 H3N2).
OC   Viruses; Riboviria; Orthornavirae; Negarnaviricota; Polyploviricotina;
OC   Insthoviricetes; Articulavirales; Orthomyxoviridae; Alphainfluenzavirus.
OX   NCBI_TaxID=38973;
OH   NCBI_TaxID=8782; Aves.
OH   NCBI_TaxID=9721; Cetacea (whales).
OH   NCBI_TaxID=9606; Homo sapiens (Human).
OH   NCBI_TaxID=9709; Phocidae (true seals).
OH   NCBI_TaxID=9823; Sus scrofa (Pig).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX   PubMed=8474171; DOI=10.1128/jvi.67.5.2723-2729.1993;
RA   Shu L.L., Bean W.J., Webster R.G.;
RT   "Analysis of the evolution and variation of the human influenza A virus
RT   nucleoprotein gene from 1933 to 1990.";
RL   J. Virol. 67:2723-2729(1993).
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; L07347; AAA51501.1; -; Genomic_RNA.
DR   SMR; Q07531; -.
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: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.
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_0000079079"
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;  56307 MW;  6A0BA15447FFD09F CRC64;
     MASQGTKRSY EQMETDGERQ NATEIRASVG KMIDGIGRFY IQMCTELKLS DYEGRLIQNS
     LTIERMVLSA FDERRNRYLE EHPSAGKDPK KTGGPIYKRV DGKWMRELVL YDKEEIRRIW
     RQANNGDDAT RGLTHMMIWH SNLNDTTYQR TRALVRTGMD PRMCSLMQGS TLPRRSGAAG
     AAVKGVGTMV MELIRMIKRG INDRNFWRGE NGRKTRIAYE RMCNILKGKF QTAAQRAMMD
     QVRESRNPGN AEYEDLIFLA RSALILRGSV AHKSCLPACV YGPAVASGYD FEKEGYSLVG
     IDPFKLLQNS QVYSLIRPNE NPAHKSQLVW MACNSAAFED LRLLSFIRGT KVFPRGKLST
     RGVQIASNEN MDTMESSTLE LRSRYWAIRT RSGGNTNQQR ASAGQISVQP AFSVQKNLPF
     DKSTIMAAFT GNTEGRTSDM RAEIIRMMEG AKPEEVSFRG RGVFELSDEK ATNPIVPSFD
     MSNEGSYFFG DNAEEYDN