ID Q20QC9_9INFA Unreviewed; 97 AA. AC Q20QC9; DT 18-APR-2006, integrated into UniProtKB/TrEMBL. DT 18-APR-2006, sequence version 1. DT 14-OCT-2015, entry version 37. DE RecName: Full=Matrix protein 2 {ECO:0000256|RuleBase:RU361247, ECO:0000256|SAAS:SAAS00108407}; GN Name=M2 {ECO:0000313|EMBL:ABB88140.1}; OS Influenza A virus (A/wedge-tailed shearwater/Western OS Australia/2576/1979(H15N9)). OC Viruses; ssRNA viruses; ssRNA negative-strand viruses; OC Orthomyxoviridae; Influenzavirus A. OX NCBI_TaxID=352560 {ECO:0000313|EMBL:ABB88140.1}; RN [1] {ECO:0000313|EMBL:ABB88140.1} RP NUCLEOTIDE SEQUENCE. RC STRAIN=A/wedge-tailed shearwater/Western Australia/2576/1979 RC {ECO:0000313|EMBL:ABB88140.1}; 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: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; CY005406; ABB88140.1; -; 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}; 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}. FT TRANSMEM 26 48 Helical. {ECO:0000256|SAM:Phobius}. SQ SEQUENCE 97 AA; 11158 MW; FF12EFFCB4370398 CRC64; MSLLTEVETP TRNGWECKCS DSSDPLVIAA SIIGILHLIL WILDRLFFKC IYRRLKYGLK RGPSTEGVPE SMREEYRQEQ QSAVDVDDGH FVNIELE //