<p>An evidence describes the source of an annotation, e.g. an experiment that has been published in the scientific literature, an orthologous protein, a record from another database, etc.</p>
<p><a href="/manual/evidences">More...</a></p>
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<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>-Experimental evidence at protein leveli
<p>This indicates the type of evidence that supports the existence of the protein. Note that the 'protein existence' evidence does not give information on the accuracy or correctness of the sequence(s) displayed.<p><a href='/help/protein_existence' target='_top'>More...</a></p>
Select a section on the left to see content.
<p>This section provides any useful information about the protein, mostly biological knowledge.<p><a href='/help/function_section' target='_top'>More...</a></p>Functioni
Forms a proton-selective ion channel that is necessary for the efficient release of the viral genome during virus entry. After attaching to the cell surface, the virion enters the cell by endocytosis. Acidification of the endosome triggers M2 ion channel activity. The influx of protons into virion interior is believed to disrupt interactions between the viral ribonucleoprotein (RNP), matrix protein 1 (M1), and lipid bilayers, thereby freeing the viral genome from interaction with viral proteins and enabling RNA segments to migrate to the host cell nucleus, where influenza virus RNA transcription and replication occur. Also plays a role in viral proteins secretory pathway. Elevates the intravesicular pH of normally acidic compartments, such as trans-Golgi network, preventing newly formed hemagglutinin from premature switching to the fusion-active conformation.
UniRule annotation
<p>Manual validated information which has been generated by the UniProtKB automatic annotation system.</p>
<p><a href="/manual/evidences#ECO:0000255">More...</a></p>
Manual assertion according to rulesi
<p>This subsection of the <a href="http://www.uniprot.org/help/function%5Fsection">Function</a> section describes regulatory mechanisms for enzymes, transporters or microbial transcription factors, and reports the components which regulate (by activation or inhibition) the reaction.<p><a href='/help/activity_regulation' target='_top'>More...</a></p>Activity regulationi
The M2 protein from most influenza A strains is inhibited by amantadine and rimantadine, resulting in viral uncoating incapacity. Emergence of amantadine-resistant variants is usually rapid.
Sites
Feature key
Position(s)
DescriptionActions
Graphical view
Length
<p>This subsection describes interesting single amino acid sites on the sequence that are not defined in any other subsection. This subsection can be displayed in different sections ('Function', 'PTM / Processing', 'Pathology and Biotech') according to its content.<p><a href='/help/site' target='_top'>More...</a></p>Sitei
Essential for channel activity, possibly by being protonated during channel activation, and by forming the channel gate and the selective filterUniRule annotation
<p>UniProtKB Keywords constitute a <a href="http://www.uniprot.org/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='/help/keywords' target='_top'>More...</a></p>Keywordsi
R-HSA-168255, Influenza Infection R-HSA-168275, Entry of Influenza Virion into Host Cell via Endocytosis R-HSA-168288, Fusion of the Influenza Virion to the Host Cell Endosome R-HSA-168298, Release R-HSA-168302, Budding R-HSA-168303, Packaging of Eight RNA Segments R-HSA-168316, Assembly of Viral Components at the Budding Site R-HSA-168336, Uncoating of the Influenza Virion R-HSA-168874, Transport of HA trimer, NA tetramer and M2 tetramer from the endoplasmic reticulum to the Golgi Apparatus R-HSA-192823, Viral mRNA Translation
<p>This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.<p><a href='/help/names_and_taxonomy_section' target='_top'>More...</a></p>Names & Taxonomyi
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section provides an exhaustive list of all names of the protein, from commonly used to obsolete, to allow unambiguous identification of a protein.<p><a href='/help/protein_names' target='_top'>More...</a></p>Protein namesi
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section indicates the name(s) of the gene(s) that code for the protein sequence(s) described in the entry. Four distinct tokens exist: 'Name', 'Synonyms', 'Ordered locus names' and 'ORF names'.<p><a href='/help/gene_name' target='_top'>More...</a></p>Gene namesi
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section provides information on the name(s) of the organism that is the source of the protein sequence.<p><a href='/help/organism-name' target='_top'>More...</a></p>Organismi
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section shows the unique identifier assigned by the NCBI to the source organism of the protein. This is known as the 'taxonomic identifier' or 'taxid'.<p><a href='/help/taxonomic_identifier' target='_top'>More...</a></p>Taxonomic identifieri
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section contains the taxonomic hierarchical classification lineage of the source organism. It lists the nodes as they appear top-down in the taxonomic tree, with the more general grouping listed first.<p><a href='/help/taxonomic_lineage' target='_top'>More...</a></p>Taxonomic lineagei
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section only exists in viral entries and indicates the host(s) either as a specific organism or taxonomic group of organisms that are susceptible to be infected by a virus.<p><a href='/help/virus_host' target='_top'>More...</a></p>Virus hosti
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section is present for entries that are part of a <a href="http://www.uniprot.org/proteomes">proteome</a>, i.e. of a set of proteins thought to be expressed by organisms whose genomes have been completely sequenced.<p><a href='/help/proteomes_manual' target='_top'>More...</a></p>Proteomesi
UP000116373
<p>A UniProt <a href="http://www.uniprot.org/manual/proteomes%5Fmanual">proteome</a> can consist of several components.<br></br>The component name refers to the genomic component encoding a set of proteins.<p><a href='/help/proteome_component' target='_top'>More...</a></p> Componenti: Genome
<p>This section provides information on the location and the topology of the mature protein in the cell.<p><a href='/help/subcellular_location_section' target='_top'>More...</a></p>Subcellular locationi
Note:Abundantly expressed at the apical plasma membrane in infected polarized epithelial cells, in close proximity to budding and assembled virions. Minor component of virions (only 16-20 molecules/virion).UniRule annotation
<p>This subsection of the <a href="http://www.uniprot.org/help/subcellular%5Flocation%5Fsection">'Subcellular location'</a> section describes the subcellular compartment where each non-membrane region of a membrane-spanning protein is found.<p><a href='/help/topo_dom' target='_top'>More...</a></p>Topological domaini
<p>This subsection of the <a href="http://www.uniprot.org/help/subcellular%5Flocation%5Fsection">'Subcellular location'</a> section describes the extent of a membrane-spanning region of the protein. It denotes the presence of both alpha-helical transmembrane regions and the membrane spanning regions of beta-barrel transmembrane proteins.<p><a href='/help/transmem' target='_top'>More...</a></p>Transmembranei
<p>This section provides information on the disease(s) and phenotype(s) associated with a protein.<p><a href='/help/pathology_and_biotech_section' target='_top'>More...</a></p>Pathology & Biotechi
Chemistry databases
ChEMBL database of bioactive drug-like small molecules
<p>This subsection of the 'PTM / Processing' section describes the extent of a polypeptide chain in the mature protein following processing or proteolytic cleavage.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_0000078890
<p>This subsection of the PTM / Processing":/help/ptm_processing_section section describes the positions of cysteine residues participating in disulfide bonds.<p><a href='/help/disulfid' target='_top'>More...</a></p>Disulfide bondi
<p>This subsection of the <a href="http://www.uniprot.org/help/ptm%5Fprocessing%5Fsection">PTM / Processing</a> section specifies the position and type of each covalently attached glycan group (mono-, di-, or polysaccharide).<p><a href='/help/carbohyd' target='_top'>More...</a></p>Glycosylationi
<p>This subsection of the <a href="http://www.uniprot.org/help/ptm%5Fprocessing%5Fsection">PTM / Processing</a> section specifies the position(s) and the type of covalently attached lipid group(s).<p><a href='/help/lipid' target='_top'>More...</a></p>Lipidationi
<p>This subsection of the 'PTM / Processing' section specifies the position and type of each modified residue excluding <a href="http://www.uniprot.org/manual/lipid">lipids</a>, <a href="http://www.uniprot.org/manual/carbohyd">glycans</a> and <a href="http://www.uniprot.org/manual/crosslnk">protein cross-links</a>.<p><a href='/help/mod_res' target='_top'>More...</a></p>Modified residuei
<p>This section provides information on the quaternary structure of a protein and on interaction(s) with other proteins or protein complexes.<p><a href='/help/interaction_section' target='_top'>More...</a></p>Interactioni
<p>This subsection of the <a href="http://www.uniprot.org/help/interaction%5Fsection">'Interaction'</a> section provides information about the protein quaternary structure and interaction(s) with other proteins or protein complexes (with the exception of physiological receptor-ligand interactions which are annotated in the <a href="http://www.uniprot.org/help/function%5Fsection">'Function'</a> section).<p><a href='/help/subunit_structure' target='_top'>More...</a></p>Subunit structurei
Homotetramer; composed of two disulfide-linked dimers held together by non-covalent interactions. May interact with matrix protein 1.
<p>This subsection of the '<a href="http://www.uniprot.org/help/interaction%5Fsection">Interaction</a>' section provides information about binary protein-protein interactions. The data presented in this section are a quality-filtered subset of binary interactions automatically derived from the <a href="https://www.ebi.ac.uk/intact/">IntAct database</a>. It is updated at every <a href="http://www.uniprot.org/help/synchronization">UniProt release</a>.<p><a href='/help/binary_interactions' target='_top'>More...</a></p>Binary interactionsi
<p>This section provides information on the tertiary and secondary structure of a protein.<p><a href='/help/structure_section' target='_top'>More...</a></p>Structurei
Secondary structure
Legend: HelixTurnBeta strandPDB Structure known for this area
<p>This subsection of the <a href="http://www.uniprot.org/help/structure%5Fsection">'Structure'</a> section is used to indicate the positions of experimentally determined hydrogen-bonded turns within the protein sequence. These elements correspond to the DSSP secondary structure code 'T'.<p><a href='/help/turn' target='_top'>More...</a></p>Turni
<p>Information inferred from a combination of experimental and computational evidence, without manual validation.</p>
<p><a href="/manual/evidences#ECO:0000213">More...</a></p>
Automatic assertion inferred from combination of experimental and computational evidencei
<p>This subsection of the <a href="http://www.uniprot.org/help/structure%5Fsection">'Structure'</a> section is used to indicate the positions of experimentally determined beta strands within the protein sequence.<p><a href='/help/strand' target='_top'>More...</a></p>Beta strandi
<p>This section provides information on sequence similarities with other proteins and the domain(s) present in a protein.<p><a href='/help/family_and_domains_section' target='_top'>More...</a></p>Family & Domainsi
Region
Feature key
Position(s)
DescriptionActions
Graphical view
Length
<p>This subsection of the 'Family and Domains' section describes a region of interest that cannot be described in other subsections.<p><a href='/help/region' target='_top'>More...</a></p>Regioni
<p>Information which has been generated by the UniProtKB automatic annotation system, without manual validation.</p>
<p><a href="/manual/evidences#ECO:0000256">More...</a></p>
Automatic assertion according to sequence analysisi
<p>This subsection of the 'Family and Domains' section describes the position of regions of compositional bias within the protein and the particular type of amino acids that are over-represented within those regions.<p><a href='/help/compbias' target='_top'>More...</a></p>Compositional biasi
<p>This subsection of the 'Family and domains' section provides general information on the biological role of a domain. The term 'domain' is intended here in its wide acceptation, it may be a structural domain, a transmembrane region or a functional domain. Several domains are described in this subsection.<p><a href='/help/domain_cc' target='_top'>More...</a></p>Domaini
Cytoplasmic tail plays an important role in virion assembly and morphogenesis.UniRule annotation
<p>This subsection of the 'Family and domains' section provides information about the sequence similarity with other proteins.<p><a href='/help/sequence_similarities' target='_top'>More...</a></p>Sequence similaritiesi
<p>This section displays by default the canonical protein sequence and upon request all isoforms described in the entry. It also includes information pertinent to the sequence(s), including <a href="http://www.uniprot.org/help/sequence%5Flength">length</a> and <a href="http://www.uniprot.org/help/sequences">molecular weight</a>. The information is filed in different subsections. The current subsections and their content are listed below:<p><a href='/help/sequences_section' target='_top'>More...</a></p>Sequences (2)i
<p>This subsection of the <a href="http://www.uniprot.org/help/sequences%5Fsection">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> displayed by default in the entry is complete or not.<p><a href='/help/sequence_status' target='_top'>More...</a></p>Sequence statusi: Complete.
This entry describes 2
<p>This subsection of the 'Sequence' section lists the alternative protein sequences (isoforms) that can be generated from the same gene by a single or by the combination of up to four biological events (alternative promoter usage, alternative splicing, alternative initiation and ribosomal frameshifting). Additionally, this section gives relevant information on each alternative protein isoform.<p><a href='/help/alternative_products' target='_top'>More...</a></p> isoformsi produced by alternative splicing. AlignAdd to basketAdded to basket
Note:Only the first 9 residues are shared by the 2 isoforms.
This isoform has been chosen as the
<p><strong>What is the canonical sequence?</strong><p><a href='/help/canonical_and_isoforms' target='_top'>More...</a></p>canonicali sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
<p>The checksum is a form of redundancy check that is calculated
from the sequence. It is useful for tracking sequence updates.</p>
<p>It should be noted that while, in theory, two different sequences could
have the same checksum value, the likelihood that this would happen
is extremely low.</p>
<p>However UniProtKB may contain entries with identical sequences in case
of multiple genes (paralogs).</p>
<p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64)
using the generator polynomial: x<sup>64</sup> + x<sup>4</sup> + x<sup>3</sup> + x + 1.
The algorithm is described in the ISO 3309 standard.
</p>
<p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.<br />
<strong>Cyclic redundancy and other checksums</strong><br />
<a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993)</a>)</p>
Checksum:i85858F6E84A97AB8
The sequence of this isoform can be found in the external entry P03485. Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly.
<p>This subsection of the 'Sequence' section reports difference(s) between the canonical sequence (displayed by default in the entry) and the different sequence submissions merged in the entry. These various submissions may originate from different sequencing projects, different types of experiments, or different biological samples. Sequence conflicts are usually of unknown origin.<p><a href='/help/conflict' target='_top'>More...</a></p>Sequence conflicti
<p>This subsection of the 'Sequence' section describes natural variant(s) of the protein sequence.<p><a href='/help/variant' target='_top'>More...</a></p>Natural varianti
<p>This section provides links to proteins that are similar to the protein sequence(s) described in this entry at different levels of sequence identity thresholds (100%, 90% and 50%) based on their membership in UniProt Reference Clusters (<a href="http://www.uniprot.org/help/uniref">UniRef</a>).<p><a href='/help/similar_proteins_section' target='_top'>More...</a></p>Similar proteinsi
<p>This section is used to point to information related to entries and found in data collections other than UniProtKB.<p><a href='/help/cross_references_section' target='_top'>More...</a></p>Cross-referencesi
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi
R-HSA-168255, Influenza Infection R-HSA-168275, Entry of Influenza Virion into Host Cell via Endocytosis R-HSA-168288, Fusion of the Influenza Virion to the Host Cell Endosome R-HSA-168298, Release R-HSA-168302, Budding R-HSA-168303, Packaging of Eight RNA Segments R-HSA-168316, Assembly of Viral Components at the Budding Site R-HSA-168336, Uncoating of the Influenza Virion R-HSA-168874, Transport of HA trimer, NA tetramer and M2 tetramer from the endoplasmic reticulum to the Golgi Apparatus R-HSA-192823, Viral mRNA Translation
<p>This section provides general information on the entry.<p><a href='/help/entry_information_section' target='_top'>More...</a></p>Entry informationi
<p>This subsection of the 'Entry information' section provides a mnemonic identifier for a UniProtKB entry, but it is not a stable identifier. Each reviewed entry is assigned a unique entry name upon integration into UniProtKB/Swiss-Prot.<p><a href='/help/entry_name' target='_top'>More...</a></p>Entry namei
M2_I34A1
<p>This subsection of the 'Entry information' section provides one or more accession number(s). These are stable identifiers and should be used to cite UniProtKB entries. Upon integration into UniProtKB, each entry is assigned a unique accession number, which is called 'Primary (citable) accession number'.<p><a href='/help/accession_numbers' target='_top'>More...</a></p>Accessioni
<p>This subsection of the 'Entry information' section shows the date of integration of the entry into UniProtKB, the date of the last sequence update and the date of the last annotation modification ('Last modified'). The version number for both the entry and the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyi
Integrated into UniProtKB/Swiss-Prot:
January 1, 1988
Last sequence update:
November 1, 1988
Last modified:
February 23, 2022
This is version 140 of the entry and version 1 of the sequence. See complete history.
<p>This subsection of the 'Entry information' section indicates whether the entry has been manually annotated and reviewed by UniProtKB curators or not, in other words, if the entry belongs to the Swiss-Prot section of UniProtKB (<strong>reviewed</strong>) or to the computer-annotated TrEMBL section (<strong>unreviewed</strong>).<p><a href='/help/entry_status' target='_top'>More...</a></p>Entry statusi
<p>This section contains any relevant information that doesn't fit in any other defined sections<p><a href='/help/miscellaneous_section' target='_top'>More...</a></p>Miscellaneousi
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