Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-41159 misc Guardado-Calvo, Pablo; Bignon, Eduardo A.; Stettner, Eva; Jeffers, Scott Allen; Pérez-Vargas, Jimena; Pehau-Arnaudet, Gerard; Tortorici, M. Alejandra; Jestin, Jean- Luc; England, Patrick; Tischler, Nicole D.; Rey, Félix A. Mechanistic insight into bunyavirus-induced membrane fusion from structure-function analyses of the hantavirus envelope glycoprotein Gc Hantaviruses are zoonotic viruses transmitted to humans by persistently infected rodents, giving rise to serious outbreaks of hemorrhagic fever with renal syndrome (HFRS) or of hantavirus pulmonary syndrome (HPS), depending on the virus, which are associated with high case fatality rates. There is only limited knowledge about the organization of the viral particles and in particular, about the hantavirus membrane fusion glycoprotein Gc, the function of which is essential for virus entry. We describe here the X-ray structures of Gc from Hantaan virus, the type species hantavirus and responsible for HFRS, both in its neutral pH, monomeric pre-fusion conformation, and in its acidic pH, trimeric post-fusion form. The structures confirm the prediction that Gc is a class II fusion protein, containing the characteristic beta-sheet rich domains termed I, II and III as initially identified in the fusion proteins of arboviruses such as alpha-and flaviviruses. The structures also show a number of features of Gc that are distinct from arbovirus class II proteins. In particular, hantavirus Gc inserts residues from three different loops into the target membrane to drive fusion, as confirmed functionally by structure-guided mutagenesis on the HPS-inducing Andes virus, instead of having a single "fusion loop". We further show that the membrane interacting region of Gc becomes structured only at acidic pH via a set of polar and electrostatic interactions. Furthermore, the structure reveals that hantavirus Gc has an additional N-terminal "tail" that is crucial in stabilizing the post-fusion trimer, accompanying the swapping of domain III in the quaternary arrangement of the trimer as compared to the standard class II fusion proteins. The mechanistic understandings derived from these data are likely to provide a unique handle for devising treatments against these human pathogens. 2016 32 Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe 676 urn:nbn:de:kobv:517-opus4-411599 10.25932/publishup-41159 Mathematisch-Naturwissenschaftliche Fakultät OPUS4-44888 Wissenschaftlicher Artikel Guardado-Calvo, Pablo; Bignon, Eduardo A.; Stettner, Eva; Jeffers, Scott Allen; Perez-Vargas, Jimena; Pehau-Arnaudet, Gerard; Tortoric, M. Alejandra; Jestin, Jean-Luc; England, Patrick; Tischler, Nicole D.; Rey, Felix A. Mechanistic Insight into Bunyavirus-Induced Membrane Fusion from Structure-Function Analyses of the Hantavirus Envelope Glycoprotein Gc Hantaviruses are zoonotic viruses transmitted to humans by persistently infected rodents, giving rise to serious outbreaks of hemorrhagic fever with renal syndrome (HFRS) or of hantavirus pulmonary syndrome (HPS), depending on the virus, which are associated with high case fatality rates. There is only limited knowledge about the organization of the viral particles and in particular, about the hantavirus membrane fusion glycoprotein Gc, the function of which is essential for virus entry. We describe here the X-ray structures of Gc from Hantaan virus, the type species hantavirus and responsible for HFRS, both in its neutral pH, monomeric pre-fusion conformation, and in its acidic pH, trimeric post-fusion form. The structures confirm the prediction that Gc is a class II fusion protein, containing the characteristic beta-sheet rich domains termed I, II and III as initially identified in the fusion proteins of arboviruses such as alpha-and flaviviruses. The structures also show a number of features of Gc that are distinct from arbovirus class II proteins. In particular, hantavirus Gc inserts residues from three different loops into the target membrane to drive fusion, as confirmed functionally by structure-guided mutagenesis on the HPS-inducing Andes virus, instead of having a single "fusion loop". We further show that the membrane interacting region of Gc becomes structured only at acidic pH via a set of polar and electrostatic interactions. Furthermore, the structure reveals that hantavirus Gc has an additional N-terminal "tail" that is crucial in stabilizing the post-fusion trimer, accompanying the swapping of domain III in the quaternary arrangement of the trimer as compared to the standard class II fusion proteins. The mechanistic understandings derived from these data are likely to provide a unique handle for devising treatments against these human pathogens. San Fransisco PLoS 2016 32 PLoS Pathogens 12 153 166 10.1371/journal.ppat.1005813 Institut für Biochemie und Biologie OPUS4-61802 Wissenschaftlicher Artikel Petazzi, Roberto Arturo; Koikkarah Aji, Amit; Tischler, Nicole D.; Chiantia, Salvatore Detection of envelope glycoprotein assembly from old world hantaviruses in the Golgi apparatus of living cells Hantaviruses are emerging pathogens that occasionally cause deadly outbreaks in the human population. While the structure of the viral envelope has been characterized with high precision, protein-protein interactions leading to the formation of new virions in infected cells are not fully understood. We used quantitative fluorescence microscopy (i.e., number and brightness analysis and fluorescence fluctuation spectroscopy) to monitor the interactions that lead to oligomeric spike complex formation in the physiological context of living cells. To this aim, we quantified protein-protein interactions for the glycoproteins Gn and Gc from Puumala and Hantaan orthohantaviruses in several cellular models. The oligomerization of each protein was analyzed in relation to subcellular localization, concentration, and the concentration of its interaction partner. Our results indicate that, when expressed separately, Gn and Gc form, respectively, homo-tetrameric and homo-dimeric complexes, in a concentration-dependent manner. Site-directed mutations or deletion mutants showed the specificity of their homotypic interactions. When both glycoproteins were coexpressed, we observed in the Golgi apparatus clear indication of GnGc interactions and the formation of Gn-Gc multimeric protein complexes of different sizes, while using various labeling schemes to minimize the influence of the fluorescent tags. Such large glycoprotein multimers may be identified as multiple Gn viral spikes interconnected via Gc-Gc contacts. This observation provides the possible first evidence for the initial assembly steps of the viral envelope within this organelle, and does so directly in living cells.
IMPORTANCE In this work, we investigate protein-protein interactions that drive the assembly of the hantavirus envelope. These emerging pathogens have the potential to cause deadly outbreaks in the human population. Therefore, it is important to improve our quantitative understanding of the viral assembly process in infected cells, from a molecular point of view. By applying advanced fluorescence microscopy methods, we monitored the formation of viral spike complexes in different cell types. Our data support a model for hantavirus assembly according to which viral spikes are formed via the clustering of hetero-dimers of the two viral glycoproteins Gn and Gc. Furthermore, the observation of large Gn-Gc hetero-multimers provide the possible first evidence for the initial assembly steps of the viral envelope, directly in the Golgi apparatus of living cells. Baltimore, Md. American Society for Microbiology 2021 18 Journal of virology 95 4 10.1128/JVI.01238-20 Institut für Biochemie und Biologie