ID D0FHX1_9INFA Unreviewed; 62 AA. AC D0FHX1; DT 24-NOV-2009, integrated into UniProtKB/TrEMBL. DT 24-NOV-2009, sequence version 1. DT 23-MAY-2018, entry version 33. DE RecName: Full=Matrix protein 2 {ECO:0000256|SAAS:SAAS01040803}; DE Flags: Fragment; GN Name=M2 {ECO:0000313|EMBL:ACX47411.1}; OS Influenza A virus (A/Chengdu/03/2009(H1N1)). OC Viruses; ssRNA viruses; ssRNA negative-strand viruses; OC Orthomyxoviridae; Alphainfluenzavirus. OX NCBI_TaxID=681159 {ECO:0000313|EMBL:ACX47411.1}; RN [1] {ECO:0000313|EMBL:ACX47411.1} RP NUCLEOTIDE SEQUENCE. RC STRAIN=A/Chengdu/03/2009 {ECO:0000313|EMBL:ACX47411.1}; RA Jiang T., Qin C., Li X., Zhao H., Yu M., Deng Y., Yu X., Han J., RA Qin E., Zhu Q.; RT "A community transmission of influenza A (H1N1) virus in a boarding RT school in China, 22-27 July 2009."; RL Submitted (OCT-2009) to the EMBL/GenBank/DDBJ databases. 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. {ECO:0000256|SAAS:SAAS01040783}. 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|SAAS:SAAS01040791}. CC -!- SUBCELLULAR LOCATION: Host apical cell membrane CC {ECO:0000256|SAAS:SAAS01040793}; Single-pass type III membrane CC protein {ECO:0000256|SAAS:SAAS01040793}. Virion membrane CC {ECO:0000256|SAAS:SAAS01040800}. CC -!- SIMILARITY: Belongs to the influenza viruses matrix protein M2 CC family. {ECO:0000256|SAAS:SAAS01040773}. 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; GU056984; ACX47411.1; -; Viral_cRNA. 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:0044385; C:integral to membrane of host cell; IEA:UniProtKB-KW. DR GO; GO:0055036; C:virion membrane; IEA:UniProtKB-SubCell. DR GO; GO:0005216; F:ion channel activity; IEA:UniProtKB-KW. DR GO; GO:0015078; F:proton transmembrane transporter activity; IEA:InterPro. DR GO; GO:0039707; P:pore formation by virus in membrane of host cell; IEA:UniProtKB-KW. DR GO; GO:0051259; P:protein complex oligomerization; IEA:UniProtKB-KW. 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:SAAS01040795}; KW Host cell membrane {ECO:0000256|SAAS:SAAS01040804}; KW Host membrane {ECO:0000256|SAAS:SAAS01040762}; KW Host-virus interaction {ECO:0000256|SAAS:SAAS01040805}; KW Hydrogen ion transport {ECO:0000256|SAAS:SAAS01040774}; KW Inhibition of host autophagy by virus {ECO:0000256|SAAS:SAAS01040755}; KW Ion channel {ECO:0000256|SAAS:SAAS01040776}; KW Ion transport {ECO:0000256|SAAS:SAAS01040807}; KW Membrane {ECO:0000256|SAAS:SAAS01040794, ECO:0000256|SAM:Phobius}; KW Transmembrane {ECO:0000256|SAAS:SAAS01040784, KW ECO:0000256|SAM:Phobius}; KW Transmembrane helix {ECO:0000256|SAAS:SAAS01040757, KW ECO:0000256|SAM:Phobius}; Transport {ECO:0000256|SAAS:SAAS01040788}; KW Viral ion channel {ECO:0000256|SAAS:SAAS01040754}; KW Virion {ECO:0000256|SAAS:SAAS01040766}. FT TRANSMEM 19 39 Helical. {ECO:0000256|SAM:Phobius}. FT NON_TER 1 1 {ECO:0000313|EMBL:ACX47411.1}. FT NON_TER 62 62 {ECO:0000313|EMBL:ACX47411.1}. SQ SEQUENCE 62 AA; 7156 MW; 28048D6BEEF42A1A CRC64; PTRSEWECRC SDSSDPLVIA ANIIGILHLI LWITDRLFFK CIYRRFKYGL KRGPSTEGVP ES //