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Annotation rule MF_04072
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General rule information [?]

Accession MF_04072
Dates 20-APR-2017 (Created)
20-NOV-2019 (Last updated, Version 5)
Name INFV_HEMA
Scope
Viruses; Orthomyxoviridae
Templates P03452 (HEMA_I34A1); P03465 (HEMA_INCCA): [Recover all]

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
HEMA
case <OC:Alphainfluenzavirus> or <OC:Betainfluenzavirus>
Protein name
RecName: Full=Hemagglutinin;
Contains:
RecName: Full=Hemagglutinin HA1 chain;
Contains:
RecName: Full=Hemagglutinin HA2 chain;
Flags: Precursor;
Gene name
HA
else
Protein name
RecName: Full=Hemagglutinin-esterase-fusion glycoprotein;
Short=HEF;
EC 3.1.1.53;
Contains:
RecName: Full=Hemagglutinin-esterase-fusion glycoprotein chain 1;
Short=HEF1;
Contains:
RecName: Full=Hemagglutinin-esterase-fusion glycoprotein chain 2;
Short=HEF2;
Flags: Precursor;
Gene name
HE
end case

Comments [?]

case <OC:Alphainfluenzavirus>
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.
Subunit Homotrimer of disulfide-linked HA1-HA2.
Subcellular location Virion membrane; Single-pass type I membrane protein. Host apical cell 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.
Ptm 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 Clara cells.
Palmitoylated.
else case <OC:Betainfluenzavirus>
Function Binds to sialic acid-containing receptors on the cell surface, bringing about the attachment of the virus particle to the cell. 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 induce an irreversible conformational change in HA2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore.
Subunit Homotrimer of disulfide-linked HA1-HA2.
Subcellular location Virion membrane; Single-pass type I membrane protein. Host apical cell 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.
Ptm 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 Clara cells.
Palmitoylated.
else case <OC:Gammainfluenzavirus>
Function Binds to the N-acetyl-9-O-acetylneuraminic acid residues on the cell surface, bringing about the attachment of the virus particle to the cell. 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 induce an irreversible conformational change in HEF2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore. Displays a receptor-destroying activity which is a neuraminidate-O-acetyl esterase. This activity cleaves off any receptor on the cell surface, which would otherwise prevent virions release. These cleavages prevent self-aggregation and ensure the efficient spread of the progeny virus from cell to cell.
Catalytic activity RHEA:22600: H2O + N-acetyl-9-O-acetylneuraminate = acetate + H(+) + N-acetylneuraminate
EC 3.1.1.53
RHEA:25564: H2O + N-acetyl-4-O-acetylneuraminate = acetate + H(+) + N-acetylneuraminate
EC 3.1.1.53
Subunit Homotrimer of disulfide-linked HEF1-HEF2.
Subcellular location Virion membrane; Single-pass type I membrane protein. Host cell membrane; Single-pass type I membrane protein.
Ptm In natural infection, inactive HEF is matured into HEF1 and HEF2 outside the cell by one or more trypsin-like, arginine-specific endoprotease.
end case
Similarity Belongs to the influenza viruses hemagglutinin family.

Keywords [?]

case <OC:Alphainfluenzavirus>
end case
case <OC:Alphainfluenzavirus> or <OC:Betainfluenzavirus>
end case
case <OC:Gammainfluenzavirus>
end case

Gene Ontology [?]

GO:0020002; Cellular component: host cell plasma membrane.
GO:0016021; Cellular component: integral component of membrane.
GO:0019031; Cellular component: viral envelope.
GO:0046789; Molecular function: host cell surface receptor binding.
case <OC:Alphainfluenzavirus>
GO:0075512; Biological process: clathrin-dependent endocytosis of virus by host cell.
end case
GO:0039654; Biological process: fusion of virus membrane with host endosome membrane.
GO:0046761; Biological process: viral budding from plasma membrane.

Cross-references [?]

PROSITE PS00001; ASN_GLYCOSYLATION; 0-unlimited; trigger=PRU00498;
Pfam PF00509; Hemagglutinin; 1;
PF03996; Hema_esterase; 1;
PF02710; Hema_HEFG; 1;
PF08720; Hema_stalk; 1;
PRINTS PR00330; HEMAGGLUTN1; 1;
PR00329; HEMAGGLUTN12; 1;
PR00331; HEMAGGLUTN2; 1;

Computed features [?]

General Signal; -; 1; trigger=yes;
Transmembrane; -; 1; trigger=yes;
ADD_TOPO_DOMAIN Extracellular; -; 1; trigger=yes;
Cytoplasmic; -; 1; trigger=yes;

Features [?]

case <OC:Alphainfluenzavirus> or <OC:Betainfluenzavirus>
From: HEMA_I34A1 (P03452)
Key     From     To       Description   Tag   Condition   FTGroup
CHAIN     18     343       Hemagglutinin HA1 chain        
CHAIN     344     565       Hemagglutinin HA2 chain        
SITE     343     344       Cleavage; by host     R-G  
LIPID     554     554       S-palmitoyl cysteine; by host     C  
LIPID     561     561       S-palmitoyl cysteine; by host     C  
LIPID     564     564       S-palmitoyl cysteine; by host     C  
DISULFID     21     480       Interchain (between HA1 and HA2 chains)     C-x*-C  
DISULFID     59     291             C-x*-C  
DISULFID     72     84             C-x*-C  
DISULFID     107     152             C-x*-C  
DISULFID     295     319             C-x*-C  
DISULFID     487     491             C-x*-C  
end case
case <OC:Gammainfluenzavirus>
From: HEMA_INCAA (P03465)
CHAIN     15     446       Hemagglutinin-esterase-fusion glycoprotein chain 1        
CHAIN     447     655       Hemagglutinin-esterase-fusion glycoprotein chain 2        
REGION     15     40       Fusion domain-1        
REGION     41     150       Esterase domain-1        
REGION     150     310       N-acetyl-9-O-acetylneuraminic acid binding        
REGION     310     364       Esterase domain-2        
REGION     365     650       Fusion domain-2        
ACT_SITE     71     71       Nucleophile        
ACT_SITE     366     366       Charge relay system        
ACT_SITE     369     369       Charge relay system        
DISULFID     20     583       Interchain (between HEF1 and HEF2 chains)     C-x*-C  
DISULFID     120     165             C-x*-C  
DISULFID     140     188             C-x*-C  
DISULFID     210     252             C-x*-C  
DISULFID     229     316             C-x*-C  
DISULFID     237     289             C-x*-C  
DISULFID     345     351             C-x*-C  
end case

Additional information [?]

Size range 560-655 amino acids
Related rules None
Fusion None