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Details on Person UniProt:P03452 HA

Class:IdReferenceGeneProduct:169083
_chainChangeLogsignal peptide:1-17 added on Fri February 6 2015;chain:18-342 added on Fri February 6 2015;chain:344-565 added on Fri February 6 2015
_displayNameUniProt:P03452 HA
_timestamp2026-02-20 22:22:18
chainsignal peptide:1-17
chain:18-565
chain:18-342
chain:344-565
checksum47F34821748F494E
commentFUNCTION 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. Interacts with human CACNA1C (PubMed:29779930).INTERACTION 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 Palmitoylated.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 club cells.MISCELLANEOUS Major glycoprotein, comprises over 80% of the envelope proteins present in virus particle.MISCELLANEOUS The extent of infection into host organism is determined by HA. Influenza viruses bud from the apical surface of polarized epithelial cells (e.g. bronchial epithelial cells) into lumen of lungs and are therefore usually pneumotropic. The reason is that HA is cleaved by tryptase clara which is restricted to lungs. However, HAs of H5 and H7 pantropic avian viruses subtypes can be cleaved by furin and subtilisin-type enzymes, allowing the virus to grow in other organs than lungs.MISCELLANEOUS The influenza A genome consists of 8 RNA segments. Genetic variation of hemagglutinin and/or neuraminidase genes results in the emergence of new influenza strains. The mechanism of variation can be the result of point mutations or the result of genetic reassortment between segments of two different strains.SIMILARITY Belongs to the influenza viruses hemagglutinin family.
created[InstanceEdit:169110] Gillespie, ME, 2005-11-22 21:39:50
descriptionrecommendedName: fullName evidence="1"Hemagglutinin component recommendedName: fullName evidence="1"Hemagglutinin HA1 chain /component component recommendedName: fullName evidence="1"Hemagglutinin HA2 chain /component
geneNameHA
identifierP03452
isSequenceChangedFALSE
keyword3D-structure
Clathrin- and caveolin-independent endocytosis of virus by host
Clathrin-mediated endocytosis of virus by host
Disulfide bond
Fusion of virus membrane with host endosomal membrane
Fusion of virus membrane with host membrane
Glycoprotein
Hemagglutinin
Host cell membrane
Host membrane
Host-virus interaction
Lipoprotein
Membrane
Palmitate
Reference proteome
Signal
Transmembrane
Transmembrane helix
Viral attachment to host cell
Viral envelope protein
Viral penetration into host cytoplasm
Virion
Virus endocytosis by host
Virus entry into host cell
modified[InstanceEdit:169470] Gillespie, ME, 2005-11-29 19:12:13
[InstanceEdit:169470] Gillespie, ME, 2005-11-29 19:12:13
[InstanceEdit:169470] Gillespie, ME, 2005-11-29 19:12:13
[InstanceEdit:169470] Gillespie, ME, 2005-11-29 19:12:13
[InstanceEdit:169487] Gillespie, ME, 2005-11-29 19:35:04
[InstanceEdit:217385] Schmidt, EE, 2008-03-27 06:23:53
[InstanceEdit:354386] Schmidt, EE, 2008-06-18 04:45:12
[InstanceEdit:384350] Kanapin, AA, 2008-11-26 14:00:39
[InstanceEdit:392885] Kanapin, AA, 2009-03-09 12:07:18
[InstanceEdit:400710] Schmidt, EE, 2009-03-25 05:33:35
[InstanceEdit:423310] Kanapin, AA
[InstanceEdit:435478] Kanapin, AA
[InstanceEdit:435871] Kanapin, AA
[InstanceEdit:447347] Kanapin, AA
[InstanceEdit:525883] Kanapin, AA
[InstanceEdit:613449] Kanapin, AA
[InstanceEdit:797602] Kanapin, AA
[InstanceEdit:937368] Yung, CK
[InstanceEdit:1042053] Yung, CK
[InstanceEdit:1220657] Yung, CK
[InstanceEdit:1300696] Yung, CK
[InstanceEdit:1301627] Yung, CK
[InstanceEdit:1551960] Weiser, JD
[InstanceEdit:1995863] Weiser, JD
[InstanceEdit:2132304] Weiser, JD
[InstanceEdit:2265580] Weiser, JD
[InstanceEdit:2455454] Weiser, JD
[InstanceEdit:5433710] Weiser, JD
[InstanceEdit:5618415] Weiser, JD
[InstanceEdit:5634237] Weiser, JD
[InstanceEdit:5673015] Weiser, JD
[InstanceEdit:9015733] Weiser, JD
[InstanceEdit:9031715] D'Eustachio, Peter, 2017-12-01
[InstanceEdit:9031717] D'Eustachio, Peter, 2017-12-01
[InstanceEdit:9037114] Weiser, JD
[InstanceEdit:9627708] Weiser, JD
[InstanceEdit:9637257] Weiser, JD
[InstanceEdit:9676415] Weiser, JD
[InstanceEdit:9730071] Weiser, JD
[InstanceEdit:9819394] Weiser, Joel
[InstanceEdit:9852000] Weiser, Joel, 2023-11-03
[InstanceEdit:9963647] Weiser, Joel, 2025-08-15
[InstanceEdit:9983091] Weiser, Joel, 2026-02-20
nameHA
referenceDatabase[ReferenceDatabase:2] UniProt
secondaryIdentifierHEMA_I34A1
A4GXH4
Q20N38
Q83964
Q8JUU5
sequenceLength565
species[Species:9031716] Influenza A virus
(referenceEntity)[EntityWithAccessionedSequence:169090] HA1 [cytosol] [Influenza A virus]
[EntityWithAccessionedSequence:169108] HA2 [cytosol] [Influenza A virus]
[EntityWithAccessionedSequence:169125] HA Precursor [cytosol] [Influenza A virus]
[EntityWithAccessionedSequence:169250] HA1 [extracellular region] [Influenza A virus]
[EntityWithAccessionedSequence:169252] HA2 [extracellular region] [Influenza A virus]
[EntityWithAccessionedSequence:189154] HA2 [endosome lumen] [Influenza A virus]
[EntityWithAccessionedSequence:189159] HA2 competent for fusion [Influenza A virus]
[EntityWithAccessionedSequence:189165] HA1 [endocytic vesicle membrane] [Influenza A virus]
[EntityWithAccessionedSequence:189173] HA1 [endosome lumen] [Influenza A virus]
[EntityWithAccessionedSequence:189175] Inter-Membrane Spanning HA2 [endocytic vesicle membrane] [Influenza A virus]
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No pathways have been reviewed or authored by UniProt:P03452 HA (169083)