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/Henry/1936 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)DescriptionActionsGraphical viewLength
Sitei37Essential for channel activity, possibly by being protonated during channel activation, and by forming the channel gate and the selective filterBy similarity1
Sitei41Seems to be involved in pH gatingBy similarity1

GO - Molecular functioni

GO - Biological processi

Keywordsi

Molecular functionIon channel
Biological processHost-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/Henry/1936 H1N1)
Taxonomic identifieri425562 [NCBI]
Taxonomic lineageiVirusesssRNA virusesssRNA negative-strand virusesOrthomyxoviridaeInfluenzavirus A
Virus hostiAves [TaxID: 8782]
Homo sapiens (Human) [TaxID: 9606]
Sus scrofa (Pig) [TaxID: 9823]
Proteomesi
  • UP000008213 Componenti: Genome
  • UP000144575 Componenti: Segment 7

Subcellular locationi

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini1 – 22Virion surfaceSequence analysisAdd BLAST22
Transmembranei23 – 43Helical; Signal-anchor for type III membrane proteinSequence analysisAdd BLAST21
Topological domaini44 – 97IntravirionSequence analysisAdd BLAST54

GO - Cellular componenti

Keywords - Cellular componenti

Host cell membrane, Host membrane, Membrane, Virion

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00003729191 – 97Matrix protein 2Add BLAST97

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi17Interchain (with C-17)By similarity
Disulfide bondi19Interchain (with C-19)By similarity
Glycosylationi20N-linked (GlcNAc...); by hostSequence analysis1
Lipidationi50S-palmitoyl cysteine; by hostBy similarity1
Modified residuei64Phosphoserine; by hostBy similarity1
Modified residuei82Phosphoserine; by hostBy similarity1
Modified residuei93Phosphoserine; by hostBy similarity1

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

ProteinModelPortaliA4GCI7.
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

Phylogenomic databases

OrthoDBiVOG09040007.

Family and domain databases

InterProiView protein in InterPro
IPR002089. Flu_M2.
PfamiView protein in Pfam
PF00599. Flu_M2. 1 hit.
ProDomiView protein in ProDom or Entries sharing at least one domain
PD001031. Flu_M2. 1 hit.

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: A4GCI7-1) [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 GSSDPLVIAA NIIGILHLIL WILDRLFFKC
60 70 80 90
IYRLFEYGLK RGPSTEGVPE SMREEYRKEQ QSAVDADDGH FVSIELE
Length:97
Mass (Da):11,131
Last modified:April 17, 2007 - v1
Checksum:i9E9A7B45D61638C7
GO
Isoform M1 (identifier: A4GCI8-1) [UniParc]FASTAAdd to basket
The sequence of this isoform can be found in the external entry A4GCI8.
Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly.
Length:252
Mass (Da):27,865
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
CY020446 Viral cRNA. Translation: ABO38353.1.

Keywords - Coding sequence diversityi

Alternative splicing

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
CY020446 Viral cRNA. Translation: ABO38353.1.

3D structure databases

ProteinModelPortaliA4GCI7.
ModBaseiSearch...
MobiDBiSearch...

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Phylogenomic databases

OrthoDBiVOG09040007.

Family and domain databases

InterProiView protein in InterPro
IPR002089. Flu_M2.
PfamiView protein in Pfam
PF00599. Flu_M2. 1 hit.
ProDomiView protein in ProDom or Entries sharing at least one domain
PD001031. Flu_M2. 1 hit.
ProtoNetiSearch...

Entry informationi

Entry nameiM2_I36A0
AccessioniPrimary (citable) accession number: A4GCI7
Entry historyiIntegrated into UniProtKB/Swiss-Prot: May 5, 2009
Last sequence update: April 17, 2007
Last modified: February 15, 2017
This is version 39 of the entry and version 1 of the sequence. See 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

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 one 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.