Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Matrix protein 2

Gene

M2

Organism
Influenza A virus (strain A/USA:Albany/12/1951 H1N1)
Status
Reviewed-Annotation score: Annotation score: 4 out of 5-Protein inferred from homologyi

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 (By similarity).By similarity

Enzyme 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 keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sitei37 – 371Essential for channel activity, possibly by being protonated during channel activation, and by forming the channel gate and the selective filterBy similarity
Sitei41 – 411Seems to be involved in pH gatingBy similarity

GO - Molecular functioni

GO - Biological processi

Complete GO annotation...

Keywords - Molecular functioni

Ion channel

Keywords - Biological processi

Host-virus interaction, Hydrogen ion transport, Inhibition of host autophagy by virus, Ion transport, Transport

Names & Taxonomyi

Protein namesi
Recommended name:
Matrix protein 2
Gene namesi
Name:M2
OrganismiInfluenza A virus (strain A/USA:Albany/12/1951 H1N1)
Taxonomic identifieri425580 [NCBI]
Taxonomic lineageiVirusesssRNA virusesssRNA negative-strand virusesOrthomyxoviridaeInfluenzavirus A
Virus hostiAves [TaxID: 8782]
Homo sapiens (Human) [TaxID: 9606]
Sus scrofa (Pig) [TaxID: 9823]
ProteomesiUP000007556 Componenti: Genome

Subcellular locationi

Topology

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Topological domaini1 – 2222Virion surfaceSequence AnalysisAdd
BLAST
Transmembranei23 – 4321Helical; Signal-anchor for type III membrane proteinSequence AnalysisAdd
BLAST
Topological domaini44 – 9754IntravirionSequence AnalysisAdd
BLAST

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti

Host cell membrane, Host membrane, Membrane, Virion

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 9797Matrix protein 2PRO_0000372923Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Disulfide bondi17 – 17Interchain (with C-17)By similarity
Disulfide bondi19 – 19Interchain (with C-19)By similarity
Glycosylationi20 – 201N-linked (GlcNAc...); by hostSequence Analysis
Lipidationi50 – 501S-palmitoyl cysteine; by hostBy similarity
Modified residuei64 – 641Phosphoserine; by hostBy similarity
Modified residuei82 – 821Phosphoserine; by hostBy similarity

Keywords - PTMi

Disulfide bond, Glycoprotein, Lipoprotein, Palmitate, Phosphoprotein

Interactioni

Subunit structurei

Homotetramer; composed of two disulfide-linked dimers held together by non-covalent interactions. May interact with matrix protein 1 (By similarity).By similarity

Structurei

3D structure databases

ProteinModelPortaliA4U7A7.
SMRiA4U7A7. Positions 23-60.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domaini

Cytoplasmic tail plays an important role in virion assembly and morphogenesis.By similarity

Sequence similaritiesi

Keywords - Domaini

Signal-anchor, Transmembrane, Transmembrane helix

Family and domain databases

InterProiIPR002089. Flu_M2.
[Graphical view]
PfamiPF00599. Flu_M2. 1 hit.
[Graphical view]
ProDomiPD001031. Flu_M2. 1 hit.
[Graphical view] [Entries sharing at least one domain]

Sequences (2)i

Sequence statusi: Complete.

This entry describes 2 isoformsi produced by alternative splicing. AlignAdd to basket

Note: Only the first 9 residues are shared by the 2 isoforms.

Isoform M2 (identifier: A4U7A7-1) [UniParc]FASTAAdd to basket

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

« Hide

        10         20         30         40         50
MSLLTEVETP IRNEWGCRCN DSSDPLVVAA SIIGILHLIL WILDRLFFKC
60 70 80 90
IYRLFKHGLK RGPSTEGVPE SMREEYRKEQ QSAVDADDSH FVNIELE
Length:97
Mass (Da):11,178
Last modified:May 15, 2007 - v1
Checksum:i3CD02057E22994A4
GO
Isoform M1 (identifier: A4U7A8-1) [UniParc]FASTAAdd to basket

The sequence of this isoform can be found in the external entry A4U7A8.
Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly.
Length:252
Mass (Da):27,834
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
CY021822 Viral cRNA. Translation: ABP49483.1.

Keywords - Coding sequence diversityi

Alternative splicing

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
CY021822 Viral cRNA. Translation: ABP49483.1.

3D structure databases

ProteinModelPortaliA4U7A7.
SMRiA4U7A7. Positions 23-60.
ModBaseiSearch...
MobiDBiSearch...

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Family and domain databases

InterProiIPR002089. Flu_M2.
[Graphical view]
PfamiPF00599. Flu_M2. 1 hit.
[Graphical view]
ProDomiPD001031. Flu_M2. 1 hit.
[Graphical view] [Entries sharing at least one domain]
ProtoNetiSearch...

Publicationsi

  1. Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
  2. The NIAID Influenza Genome Sequencing Consortium
    Submitted (APR-2007) to the EMBL/GenBank/DDBJ databases
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].

Entry informationi

Entry nameiM2_I51A0
AccessioniPrimary (citable) accession number: A4U7A7
Entry historyi
Integrated into UniProtKB/Swiss-Prot: May 5, 2009
Last sequence update: May 15, 2007
Last modified: June 24, 2015
This is version 36 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Miscellaneousi

Miscellaneous

When the channel is activated, one or more imidazole moities of His-37 probably become bi-protonated.

Keywords - Technical termi

Complete proteome

Documents

  1. SIMILARITY comments
    Index of protein domains and families

External Data

Dasty 3

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into Uniref entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.