ID Q77MD4_9INFA Unreviewed; 97 AA. AC Q77MD4; DT 05-JUL-2004, integrated into UniProtKB/TrEMBL. DT 05-JUL-2004, sequence version 1. DT 27-MAY-2015, entry version 42. DE RecName: Full=Matrix protein 2 {ECO:0000256|RuleBase:RU361247, ECO:0000256|SAAS:SAAS00108407}; GN Name=M {ECO:0000313|EMBL:AAK49257.1}; OS Influenza A virus (A/Hong Kong/488/97(H5N1)). OC Viruses; ssRNA negative-strand viruses; Orthomyxoviridae; OC Influenzavirus A. OX NCBI_TaxID=155222 {ECO:0000313|EMBL:AAK49257.1}; RN [1] {ECO:0000313|EMBL:AAK49257.1} RP NUCLEOTIDE SEQUENCE. RC STRAIN=A/Hong Kong/488/97 {ECO:0000313|EMBL:AAK49257.1}; RA Shaw M.W., Cooper L.A., Xu X., Thompson W.W., Krauss S.L., Guan Y., RA Zhou N.N., Klimov A., Cox N.J., Webster R.G., Lim W., Shortridge K.F., RA Subbarao K.; RL Submitted (APR-2000) to the EMBL/GenBank/DDBJ databases. RN [2] {ECO:0000313|EMBL:AAK49257.1} RP NUCLEOTIDE SEQUENCE. RC STRAIN=A/Hong Kong/488/97 {ECO:0000313|EMBL:AAK49257.1}; RX PubMed=11748666; DOI=10.1002/jmv.2118; RA Shaw M., Cooper L., Xu X., Thompson W., Krauss S., Guan Y., Zhou N., RA Klimov A., Cox N., Webster R., Lim W., Shortridge K., Subbarao K.; RT "Molecular changes associated with the transmission of avian influenza RT a H5N1 and H9N2 viruses to humans."; RL J. Med. Virol. 66:107-114(2002). 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:SAAS00208137}. 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}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; AF255378; AAK49257.1; -; Genomic_RNA. DR EMBL; AF255377; AAK49257.1; JOINED; Genomic_RNA. DR ProteinModelPortal; Q77MD4; -. DR SMR; Q77MD4; 23-60. 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}; KW Phosphoprotein {ECO:0000256|SAAS:SAAS00108507}; KW Signal-anchor {ECO:0000256|RuleBase:RU361247}; KW Transmembrane {ECO:0000256|RuleBase:RU361247, KW ECO:0000256|SAAS:SAAS00108343}; KW Transmembrane helix {ECO:0000256|RuleBase:RU361247, KW ECO:0000256|SAAS:SAAS00108211}; KW Transport {ECO:0000256|RuleBase:RU361247, KW ECO:0000256|SAAS:SAAS00108321}; KW Virion {ECO:0000256|RuleBase:RU361247, ECO:0000256|SAAS:SAAS00108457}. SQ SEQUENCE 97 AA; 11203 MW; F4C22FD462FF0BF9 CRC64; MSLLTEVETL TRNGWGCRCS DSSDPLVVAA SIIGILHLIL WILDRLFFKC IYRRFKYGLK RGPPTEGVLE SMREEYRQEQ QNAVDVDDGH FVNIELE //