ID   Q0A3L8_9INFA            Unreviewed;        97 AA.
AC   Q0A3L8;
DT   17-OCT-2006, integrated into UniProtKB/TrEMBL.
DT   17-OCT-2006, sequence version 1.
DT   09-DEC-2015, entry version 38.
DE   RecName: Full=Matrix protein 2 {ECO:0000256|RuleBase:RU361247, ECO:0000256|SAAS:SAAS00395487};
GN   Name=M2 {ECO:0000313|EMBL:ABI84715.1};
OS   Influenza A virus (A/turkey/Minnesota/1012/1990(H13N2)).
OC   Viruses; ssRNA viruses; ssRNA negative-strand viruses;
OC   Orthomyxoviridae; Influenzavirus A.
OX   NCBI_TaxID=402492 {ECO:0000313|EMBL:ABI84715.1};
RN   [1] {ECO:0000313|EMBL:ABI84715.1}
RP   NUCLEOTIDE SEQUENCE.
RC   STRAIN=A/turkey/Minnesota/1012/1990 {ECO:0000313|EMBL:ABI84715.1};
RX   PubMed=16439620; DOI=10.1126/science.1121586;
RA   Obenauer J.C., Denson J., Mehta P.K., Su X., Mukatira S.,
RA   Finkelstein D.B., Xu X., Wang J., Ma J., Fan Y., Rakestraw K.M.,
RA   Webster R.G., Hoffmann E., Krauss S., Zheng J., Zhang Z., Naeve C.W.;
RT   "Large-scale sequence analysis of avian influenza isolates.";
RL   Science 311:1576-1580(2006).
CC   -!- FUNCTION: Forms a proton-selective ion channel that is necessary
CC       for the efficient release of the viral genome during virus entry.
CC       After attaching to the cell surface, the virion enters the cell by
CC       endocytosis. Acidification of the endosome triggers M2 ion channel
CC       activity. The influx of protons into virion interior is believed
CC       to disrupt interactions between the viral ribonucleoprotein (RNP),
CC       matrix protein 1 (M1), and lipid bilayers, thereby freeing the
CC       viral genome from interaction with viral proteins and enabling RNA
CC       segments to migrate to the host cell nucleus, where influenza
CC       virus RNA transcription and replication occur. Also plays a role
CC       in viral proteins secretory pathway. Elevates the intravesicular
CC       pH of normally acidic compartments, such as trans-Golgi network,
CC       preventing newly formed hemagglutinin from premature switching to
CC       the fusion-active conformation (By similarity).
CC       {ECO:0000256|SAAS:SAAS00395278}.
CC   -!- ENZYME REGULATION: The M2 protein from most influenza A strains is
CC       inhibited by amantadine and rimantadine, resulting in viral
CC       uncoating incapacity. Emergence of amantadine-resistant variants
CC       is usually rapid. {ECO:0000256|RuleBase:RU361247}.
CC   -!- SUBUNIT: Homotetramer; composed of two disulfide-linked dimers
CC       held together by non-covalent interactions. May interact with
CC       matrix protein 1. {ECO:0000256|RuleBase:RU361247}.
CC   -!- SUBCELLULAR LOCATION: Virion membrane
CC       {ECO:0000256|RuleBase:RU361247}. Host apical cell membrane
CC       {ECO:0000256|RuleBase:RU361247}; Single-pass type III membrane
CC       protein {ECO:0000256|RuleBase:RU361247}.
CC   -!- DOMAIN: Cytoplasmic tail plays an important role in virion
CC       assembly and morphogenesis. {ECO:0000256|RuleBase:RU361247}.
CC   -!- SIMILARITY: Belongs to the influenza viruses matrix protein M2
CC       family. {ECO:0000256|RuleBase:RU361247}.
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DR   EMBL; CY014800; ABI84715.1; -; Other_RNA.
DR   GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0055036; C:virion membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0015078; F:hydrogen ion transmembrane transporter activity; IEA:InterPro.
DR   GO; GO:0039521; P:suppression by virus of host autophagy; IEA:UniProtKB-KW.
DR   InterPro; IPR002089; Flu_M2.
DR   Pfam; PF00599; Flu_M2; 1.
DR   ProDom; PD001031; Flu_M2; 1.
PE   3: Inferred from homology;
KW   Disulfide bond {ECO:0000256|SAAS:SAAS00108279};
KW   Host cell membrane {ECO:0000256|RuleBase:RU361247,
KW   ECO:0000256|SAAS:SAAS00108156};
KW   Host membrane {ECO:0000256|RuleBase:RU361247,
KW   ECO:0000256|SAAS:SAAS00108238};
KW   Host-virus interaction {ECO:0000256|SAAS:SAAS00108165};
KW   Hydrogen ion transport {ECO:0000256|RuleBase:RU361247,
KW   ECO:0000256|SAAS:SAAS00108569};
KW   Inhibition of host autophagy by virus {ECO:0000256|SAAS:SAAS00108142};
KW   Ion channel {ECO:0000256|RuleBase:RU361247,
KW   ECO:0000256|SAAS:SAAS00108550};
KW   Ion transport {ECO:0000256|RuleBase:RU361247,
KW   ECO:0000256|SAAS:SAAS00108149};
KW   Membrane {ECO:0000256|RuleBase:RU361247,
KW   ECO:0000256|SAAS:SAAS00108449, ECO:0000256|SAM:Phobius};
KW   Signal-anchor {ECO:0000256|RuleBase:RU361247};
KW   Transmembrane {ECO:0000256|RuleBase:RU361247,
KW   ECO:0000256|SAAS:SAAS00108343, ECO:0000256|SAM:Phobius};
KW   Transmembrane helix {ECO:0000256|RuleBase:RU361247,
KW   ECO:0000256|SAAS:SAAS00108211, ECO:0000256|SAM:Phobius};
KW   Transport {ECO:0000256|RuleBase:RU361247,
KW   ECO:0000256|SAAS:SAAS00108321};
KW   Virion {ECO:0000256|RuleBase:RU361247, ECO:0000256|SAAS:SAAS00108457}.
FT   TRANSMEM     26     48       Helical. {ECO:0000256|SAM:Phobius}.
SQ   SEQUENCE   97 AA;  11136 MW;  3F4093895ED46301 CRC64;
     MSLLTEVETH TRSGWECRCS DSSDPLVIAA SIIGILHLIL WILDRLFFKC IYRRFKYGLK
     SGPSTEGVPE SMREEYQQEK QSAVDVDDGH FVNIELE
//