PMC:7712180 / 91587-94703 JSONTXT 2 Projects

Annnotations TAB TSV DIC JSON TextAE

Id Subject Object Predicate Lexical cue
T485 0-113 Sentence denotes Figure 1 Schematic structures of an IAV and its HA. (a) The virion is pleomorphic from spherical to filamentous.
T486 114-343 Sentence denotes It contains eight negative sense, single-stranded RNA genomic segments, each coated with nucleoproteins (NPs) and bound to a heterotrimeric RNA polymerase complex of PA, PB1 and PB2 that forms as a viral ribonucleoprotein (vRNP).
T487 344-401 Sentence denotes All 8 vRNPs are surrounded by a lipid bilayer (envelope).
T488 402-691 Sentence denotes Whereas the inner layer of the envelope is attached to matrix 1 (M1) proteins bound to vRNPs and to nuclear export proteins (NEPs, formerly named NS2 proteins), the outer layer is spiked with HAs and NAs and channeled with matrix 2 (M2) proteins. (b) Diagram of an unfolded HA polypeptide.
T489 692-820 Sentence denotes The signal peptide (SP) at the N-terminus is removed during the cotranslational translocation of a nascent HA into the ER [134].
T490 821-931 Sentence denotes The synthesized single polypeptide HA is designed to be HA0 (inactive form) that carries HA1 and HA2 subunits.
T491 932-1110 Sentence denotes The HA1 subunit, in addition to being a major antigen, contains a receptor binding site, which binds specifically to a sialyl glycan as indicated, except for H17 and H18 viruses.
T492 1111-1173 Sentence denotes A cleavage site (CS) is located at the end of the HA1 subunit.
T493 1174-1327 Sentence denotes The HA1 CS usually contains a single basic aa (X-R/K) that can be cleaved extracellularly by tissue-specific expressed trypsin-like serine endoproteases.
T494 1328-1769 Sentence denotes In contrast, the HA1 CS with additional basic amino acids (R/K-R) may be cleaved intracellularly by ubiquitous proteases (furin and PC5/6) in the trans-Golgi compartment recognizing the R-X-R/K-R motif or cleaved extracellularly by ubiquitous proteases (MSPL and TMPRSS13) in the plasma membrane recognizing the R/K-X-R/K-R motif, and the virus can thus cause systemic infection and is classified as a highly pathogenic (HP) virus [135,136].
T495 1770-1940 Sentence denotes After the cleavage, the HA1 and HA2 subunits remain disulfide-linked between Cys (C, red) and Cys (C, green) of the two subunits, giving the fusion-active form of the HA.
T496 1941-2066 Sentence denotes The HA2 subunit carries a hydrophobic fusion peptide (FP) at the N-terminus followed by heptad repeats 1 and 2 (HR1 and HR2).
T497 2067-2211 Sentence denotes Upon activation at low pH, these 3 regions work cooperatively to fuse viral and cellular membranes together, releasing vRNPs into the host cell.
T498 2212-2342 Sentence denotes The HA2 subunit also contains a transmembrane domain (TM) anchoring the viral membrane (envelope) and promoting full fusion [137].
T499 2343-2510 Sentence denotes A hydrophilic cytoplasmic tail (CT) at the C-terminus of the HA2 subunit can also affect the fusion process [138]. (c) Side view of a surface diagram of a trimeric HA.
T500 2511-2694 Sentence denotes This representative viral HA is from pdb ID of 3ube, which showed a 2009 pandemic HA in complex with lactoseries tetrasaccharide c (LSTc, Neu5Acα2,6Galβ1,4GlcNAcβ1,3Galβ1,4Glc) [139].
T501 2695-2847 Sentence denotes Each monomer of the HA trimer is colored as follows: deep blue, HA1 and marine blue, HA2; green smudge, HA1 and lemon, HA2; raspberry, HA1 and red, HA2.
T502 2848-3116 Sentence denotes The receptor binding site, which carries a part of the LSTc ligand (magenta stick, Neu5Ac; yellow stick, Gal; blue stick, GlcNAc; yellow stick, Gal), is located on each globular head, which is a part of HA1 on a stalk composed of the remaining part of HA1 and all HA2.