B2VM22 · B2VM22_9INFA
- ProteinMatrix protein 2
- GeneM2
- StatusUniProtKB unreviewed (TrEMBL)
- Amino acids
- Protein existenceInferred from homology
- Annotation score4/5
Function
function
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.
Miscellaneous
When the channel is activated, one or more imidazole moities of His-37 probably become bi-protonated.
Activity regulation
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.
Features
Showing features for site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Site | 37 | Essential for channel activity, possibly by being protonated during channel activation, and by forming the channel gate and the selective filter | ||||
Sequence: H | ||||||
Site | 41 | Seems to be involved in pH gating | ||||
Sequence: W |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | host cell plasma membrane | |
Cellular Component | membrane | |
Cellular Component | virion membrane | |
Molecular Function | monoatomic ion channel activity | |
Molecular Function | proton transmembrane transporter activity | |
Biological Process | protein complex oligomerization | |
Biological Process | suppression by virus of host autophagy | |
Biological Process | symbiont genome entry into host cell via pore formation in plasma membrane |
Keywords
- Molecular function
- Biological process
Names & Taxonomy
Protein names
- Recommended nameMatrix protein 2
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageViruses > Riboviria > Orthornavirae > Negarnaviricota > Polyploviricotina > Insthoviricetes > Articulavirales > Orthomyxoviridae > Alphainfluenzavirus > Alphainfluenzavirus influenzae > Influenza A virus
Accessions
- Primary accessionB2VM22
Subcellular Location
UniProt Annotation
GO Annotation
Host apical cell membrane ; Single-pass type III membrane protein
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).
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Topological domain | 1-22 | Virion surface | ||||
Sequence: MSLLTEVETPIKNEWGCRCNDS | ||||||
Transmembrane | 25-43 | Helical | ||||
Sequence: PLVVAANIIGIVHLILWII | ||||||
Topological domain | 44-97 | Intravirion | ||||
Sequence: DRLFSKSIYRIFKHGLKRGPSTEGVPESMREEYREEQQNAVDADDGHFVSIELE |
Keywords
- Cellular component
PTM/Processing
Features
Showing features for disulfide bond, glycosylation, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Disulfide bond | 17 | Interchain (with Cys-17) | ||||
Sequence: C | ||||||
Disulfide bond | 19 | Interchain (with Cys-19) | ||||
Sequence: C | ||||||
Glycosylation | 20 | N-linked (GlcNAc...) asparagine; by host | ||||
Sequence: N | ||||||
Modified residue | 64 | Phosphoserine; by host | ||||
Sequence: S | ||||||
Modified residue | 93 | Phosphoserine; by host | ||||
Sequence: S |
Keywords
- PTM
PTM databases
Interaction
Subunit
Homotetramer; composed of two disulfide-linked dimers held together by non-covalent interactions. May interact with matrix protein 1.
Structure
Family & Domains
Features
Showing features for region, compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 60-88 | Disordered | ||||
Sequence: KRGPSTEGVPESMREEYREEQQNAVDADD | ||||||
Compositional bias | 67-88 | Basic and acidic residues | ||||
Sequence: GVPESMREEYREEQQNAVDADD |
Domain
Cytoplasmic tail plays an important role in virion assembly and morphogenesis.
Sequence similarities
Belongs to the influenza viruses matrix protein M2 family.
Keywords
- Domain
Family and domain databases
Sequence
- Sequence statusComplete
- Length97
- Mass (Da)11,058
- Last updated2008-07-01 v1
- Checksum6E71BB310D818DC1
Features
Showing features for compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 67-88 | Basic and acidic residues | ||||
Sequence: GVPESMREEYREEQQNAVDADD |