Q9WCE4 · Q9WCE4_9INFA
- ProteinHemagglutinin
- GeneHA
- StatusUniProtKB unreviewed (TrEMBL)
- Amino acids566 (go to sequence)
- Protein existenceEvidence at transcript level
- Annotation score4/5
Function
function
Binds to sialic acid-containing receptors on the cell surface, bringing about the attachment of the virus particle to the cell. This attachment induces virion internalization either through clathrin-dependent endocytosis or through clathrin- and caveolin-independent pathway. Plays a major role in the determination of host range restriction and virulence. Class I viral fusion protein. Responsible for penetration of the virus into the cell cytoplasm by mediating the fusion of the membrane of the endocytosed virus particle with the endosomal membrane. Low pH in endosomes induces an irreversible conformational change in HA2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore.
Binds to sialic acid-containing receptors on the cell surface, bringing about the attachment of the virus particle to the cell. This attachment induces virion internalization of about two third of the virus particles through clathrin-dependent endocytosis and about one third through a clathrin- and caveolin-independent pathway. Plays a major role in the determination of host range restriction and virulence. Class I viral fusion protein. Responsible for penetration of the virus into the cell cytoplasm by mediating the fusion of the membrane of the endocytosed virus particle with the endosomal membrane. Low pH in endosomes induces an irreversible conformational change in HA2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore.
Features
Showing features for site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Site | 344-345 | Cleavage; by host | ||||
Sequence: RG |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | apical plasma membrane | |
Cellular Component | host cell plasma membrane | |
Cellular Component | viral envelope | |
Cellular Component | virion membrane | |
Molecular Function | host cell surface receptor binding | |
Biological Process | clathrin-dependent endocytosis of virus by host cell | |
Biological Process | fusion of virus membrane with host endosome membrane | |
Biological Process | fusion of virus membrane with host plasma membrane | |
Biological Process | viral budding from plasma membrane | |
Biological Process | virion attachment to host cell |
Keywords
- Molecular function
- Biological process
Names & Taxonomy
Protein names
- Recommended nameHemagglutinin
- Cleaved into 2 chains
Gene names
Organism names
- Strain
- Taxonomic lineageViruses > Riboviria > Orthornavirae > Negarnaviricota > Polyploviricotina > Insthoviricetes > Articulavirales > Orthomyxoviridae > Alphainfluenzavirus > Alphainfluenzavirus influenzae > Influenza A virus
Accessions
- Primary accessionQ9WCE4
Subcellular Location
UniProt Annotation
GO Annotation
Apical cell membrane ; Single-pass type I membrane protein
Cell membrane ; Single-pass type I membrane protein
Host apical cell membrane ; Single-pass type I membrane protein
Membrane ; Single-pass type I membrane protein
Virion membrane ; Single-pass type I membrane protein
Note: Targeted to the apical plasma membrane in epithelial polarized cells through a signal present in the transmembrane domain. Associated with glycosphingolipid- and cholesterol-enriched detergent-resistant lipid rafts.
Features
Showing features for transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transmembrane | 531-554 | Helical | ||||
Sequence: LAIYSTVASSLVLLVSLGAISFWM |
Keywords
- Cellular component
PTM/Processing
Features
Showing features for disulfide bond, chain, lipidation.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Disulfide bond | 72↔84 | |||||
Sequence: CNVAGWILGNPEC | ||||||
Disulfide bond | 296↔320 | |||||
Sequence: CQTPRGALNSSLPFQNIHPITIGEC | ||||||
Chain | PRO_5023440410 | 345-566 | Hemagglutinin HA2 chain | |||
Sequence: GLFGAIAGFIEGGWTGMIDGWYGYHHQNEQGSGYAADQKSTQNAIDGITNKVNSVIEKMNTQFTAVGKEFNNLERRIENLNKKVDDGFLDVWTYNAELLVLLENERTLDFHDSNVRNLYEKVKSQLRNNAKEIGNGCFEFYHKCDDECMESVKNGTYDYPKYSEESKLNREEIDGVKLESMGVYQILAIYSTVASSLVLLVSLGAISFWMCSNGSLQCRICI | ||||||
Disulfide bond | 488↔492 | |||||
Sequence: CDDEC | ||||||
Lipidation | 555 | S-palmitoyl cysteine; by host | ||||
Sequence: C | ||||||
Lipidation | 562 | S-palmitoyl cysteine; by host | ||||
Sequence: C | ||||||
Lipidation | 565 | S-palmitoyl cysteine; by host | ||||
Sequence: C |
Post-translational modification
In natural infection, inactive HA is matured into HA1 and HA2 outside the cell by one or more trypsin-like, arginine-specific endoprotease secreted by the bronchial epithelial cells. One identified protease that may be involved in this process is secreted in lungs by club cells.
Palmitoylated.
Keywords
- PTM
Interaction
Subunit
Homotrimer of disulfide-linked HA1-HA2.
Sequence
- Sequence statusComplete
- Length566
- Mass (Da)63,059
- Last updated1999-11-01 v1
- ChecksumD54798AA516F46AC