6gol
From Proteopedia
Three dimensional structure of a novel influenza hemagglutinin tri-stalk protein
Structural highlights
Function[D3G5J5_9INFA] 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.[HAMAP-Rule:MF_04072][SAAS:SAAS01039073] 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.[RuleBase:RU003324] Publication Abstract from PubMedLong alpha helix (LAH) from influenza virus hemagglutinin (HA) stem or stalk domain is one of the most conserved influenza virus antigens. Expression of N-terminally extended LAH in E. coli leads to assembly of alpha-h elical homotrimer which is structurally nearly identical to the corresponding region of post-fusion form of native HA. This novel tri-stalk protein was able to differentiate between group 1 and 2 influenza in ELISA with virus-infected mice sera. It was also successfully applied for enzyme-linked immunospot assay to estimate the number of HA stem-reactive antibody (Ab)-secreting cells in mice. An in-house indirect ELISA was developed using a HA tri-stalk protein as a coating antigen for evaluation of HA stem-specific Ab levels in human sera collected in Luxembourg from 211 persons with occupational exposure to swine before the pandemic H1N1/09 virus had spread to Western Europe. Our results show that 70% of these pre-pandemic sera are positive for HA stem-specific Abs. In addition, levels of HA stem-specific Abs have positive correlation with the corresponding IgG titers and neutralizing activities against pandemic H1N1/09 virus. Structure and applications of novel influenza HA tri-stalk protein for evaluation of HA stem-specific immunity.,Lu IN, Kirsteina A, Farinelle S, Willieme S, Tars K, Muller CP, Kazaks A PLoS One. 2018 Sep 27;13(9):e0204776. doi: 10.1371/journal.pone.0204776., eCollection 2018. PMID:30261065[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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