Matches in SemOpenAlex for { <https://semopenalex.org/work/W3155323557> ?p ?o ?g. }
Showing items 1 to 78 of
78
with 100 items per page.
- W3155323557 abstract "Retrovirus entry follows receptor binding by the surface-exposed glycoprotein, which triggers the transmembrane glycoprotein (TM) to refold into a membrane fusion-active state. The trimer of hairpins is the best-characterized TM protein conformer and is composed of a central trimeric coiled coil associated with an outer antiparallel layer of 3 C-terminal segments. The trimer of hairpins represents the end point of a refolding pathway that apposes and catalyses fusion of the virus and cell membranes. The structure of pretriggered or „prefusion‟ TM is unknown.Cysteine replacement mutagenesis was applied to the human T cell leukemia virus type 1 TM, gp21, to ask if it resembles the prefusion form of its structural homologue, Ebola virus GP2, which is maintained as a trimer via a short coiled coil. Structural homology predicted that Ala-375 of gp21 is at the N-terminus of a corresponding short coiled coil and is oriented towards the 3-fold symmetry axis. The A375C substitution enabled interprotomer disulfide bonding, indicating that gp21 protomers are in close proximity in the Ala-375 region. I propose that prefusion gp21 resembles GP2 with a short coiled coil maintaining trimerization and functioning as a structural scaffold for the transition to fusion-active conformations.The fusion activation of the human immunodeficiency virus type-1 TM, gp41, involves its transition to the trimer of hairpins via a prehairpin intermediate. Cysteine-replacement mutagenesis was used to examine the structures of prefusion gp41 and recombinant models of the prehairpin and trimer of hairpins. The T569C mutation, in the C-terminal segment of the predicted coiled coil enabled quantitative interprotomer disulfide bonding in prefusion gp41, whereas T538C in the N-terminal region did not. Thus the coiled coil appears to be also present in prefusion gp41. By contrast, S538C led to efficient interprotomer disulfide formation in the prehairpin and trimer of hairpins. Threonine-538 is within the N-terminal “polar segment” which mediates functionally important hydrophobic interactions with the membrane-proximal ectodomain region (MPER) in the trimer of hairpins. A model for gp41 conformational activation is proposed, whereby a trimeric coiled coil in prefusion gp41 becomes extended into the polar segment in the prehairpin, providing a packing surface for C-terminal sequences to form a hairpin structure that extends to the terminal membrane-interactive sequences.The disulfide-bonded region (DSR) of gp41 mediates association with the receptor-binding glycoprotein, gp120, and transmission of the activation signal from receptor-bound gp120. Forced evolution of the W596L.K601D DSR mutant that lacks gp120-gp41 association, was used to identify functional determinants that are linked to the DSR and therefore may be involved in the activation process. A D601H pseudoreversion in the DSR restored gp120-gp41 association but required an additional D674E mutation in the MPER for optimised replication competence. In an independent culture, D601H emerged together with D674N and deletion of Thr-389-Trp-390 in variable region 4 of gp120. Conservative substitutions at Asp-674 modulated virus entry in the context of W596L.K601H, indicating for the first time that the MPER is functionally linked to the association/activation synapse of gp120-gp41. My results reveal new information about the fusion-activation mechanism employed by retroviruses." @default.
- W3155323557 created "2021-04-26" @default.
- W3155323557 creator A5053081401 @default.
- W3155323557 date "2017-05-18" @default.
- W3155323557 modified "2023-09-24" @default.
- W3155323557 title "Studies on the activation mechanism of the HIV-1 membrane fusion glycoprotein, gp41" @default.
- W3155323557 doi "https://doi.org/10.4225/03/58a67eba36cb6" @default.
- W3155323557 hasPublicationYear "2017" @default.
- W3155323557 type Work @default.
- W3155323557 sameAs 3155323557 @default.
- W3155323557 citedByCount "0" @default.
- W3155323557 crossrefType "dissertation" @default.
- W3155323557 hasAuthorship W3155323557A5053081401 @default.
- W3155323557 hasConcept C103038307 @default.
- W3155323557 hasConcept C104317684 @default.
- W3155323557 hasConcept C108625454 @default.
- W3155323557 hasConcept C122146531 @default.
- W3155323557 hasConcept C12554922 @default.
- W3155323557 hasConcept C147483822 @default.
- W3155323557 hasConcept C167625842 @default.
- W3155323557 hasConcept C178790620 @default.
- W3155323557 hasConcept C185592680 @default.
- W3155323557 hasConcept C195616568 @default.
- W3155323557 hasConcept C2776258796 @default.
- W3155323557 hasConcept C2776403692 @default.
- W3155323557 hasConcept C2777339483 @default.
- W3155323557 hasConcept C2779546866 @default.
- W3155323557 hasConcept C41625074 @default.
- W3155323557 hasConcept C54355233 @default.
- W3155323557 hasConcept C55493867 @default.
- W3155323557 hasConcept C55988834 @default.
- W3155323557 hasConcept C86803240 @default.
- W3155323557 hasConceptScore W3155323557C103038307 @default.
- W3155323557 hasConceptScore W3155323557C104317684 @default.
- W3155323557 hasConceptScore W3155323557C108625454 @default.
- W3155323557 hasConceptScore W3155323557C122146531 @default.
- W3155323557 hasConceptScore W3155323557C12554922 @default.
- W3155323557 hasConceptScore W3155323557C147483822 @default.
- W3155323557 hasConceptScore W3155323557C167625842 @default.
- W3155323557 hasConceptScore W3155323557C178790620 @default.
- W3155323557 hasConceptScore W3155323557C185592680 @default.
- W3155323557 hasConceptScore W3155323557C195616568 @default.
- W3155323557 hasConceptScore W3155323557C2776258796 @default.
- W3155323557 hasConceptScore W3155323557C2776403692 @default.
- W3155323557 hasConceptScore W3155323557C2777339483 @default.
- W3155323557 hasConceptScore W3155323557C2779546866 @default.
- W3155323557 hasConceptScore W3155323557C41625074 @default.
- W3155323557 hasConceptScore W3155323557C54355233 @default.
- W3155323557 hasConceptScore W3155323557C55493867 @default.
- W3155323557 hasConceptScore W3155323557C55988834 @default.
- W3155323557 hasConceptScore W3155323557C86803240 @default.
- W3155323557 hasLocation W31553235571 @default.
- W3155323557 hasOpenAccess W3155323557 @default.
- W3155323557 hasPrimaryLocation W31553235571 @default.
- W3155323557 hasRelatedWork W1837383530 @default.
- W3155323557 hasRelatedWork W1986025310 @default.
- W3155323557 hasRelatedWork W1999015961 @default.
- W3155323557 hasRelatedWork W2008506402 @default.
- W3155323557 hasRelatedWork W2012272056 @default.
- W3155323557 hasRelatedWork W2013835478 @default.
- W3155323557 hasRelatedWork W2016031063 @default.
- W3155323557 hasRelatedWork W2029665087 @default.
- W3155323557 hasRelatedWork W2050310658 @default.
- W3155323557 hasRelatedWork W2061544225 @default.
- W3155323557 hasRelatedWork W2076016977 @default.
- W3155323557 hasRelatedWork W2097070131 @default.
- W3155323557 hasRelatedWork W2129221926 @default.
- W3155323557 hasRelatedWork W2144752281 @default.
- W3155323557 hasRelatedWork W2148855383 @default.
- W3155323557 hasRelatedWork W2334706215 @default.
- W3155323557 hasRelatedWork W2476105399 @default.
- W3155323557 hasRelatedWork W2583147894 @default.
- W3155323557 hasRelatedWork W2784115483 @default.
- W3155323557 hasRelatedWork W2740255545 @default.
- W3155323557 isParatext "false" @default.
- W3155323557 isRetracted "false" @default.
- W3155323557 magId "3155323557" @default.
- W3155323557 workType "dissertation" @default.