Structure-Function Analysis of Herpesvirus Glycoprotein H
Final Report Abstract
Herpesvirus infection requires a species-specific receptor binding protein and the conserved fusion machinery consisting of glycoprotein B (gB) and the heterodimeric gH/gL complex. gB specifies all features of a class III fusion protein. However, in contrast to other class III fusogens gB alone is not fusion active but depends on presence of gH/gL. It is hypothesized that structural rearrangements after receptor binding activate the gH/gL complex, which then triggers gB fusogenic activity. However, many molecular details and especially the role of gH/gL remained unknown. The crystal structures of gH or gH/gL from several herpesviruses including the porcine alphaherpesvirus Pseudorabiesvirus (PrV), uncovered four highly conserved domains despite only low amino acid sequence identity. We speculated that distinct rearrangements between these domains triggers gB-mediated membrane fusion. Targeted deletion or introduction of specific mutations at various sites within gH, which prohibited the intramolecular movement supported our hypothesis. In a parallel approach, we assessed gH function by selecting for PrV revertants after repeated co-seeding of infected and non-infected cells which were capable to infect cells without gL. The identified compensatory mutations not only shed light on gH/gL function in membrane fusion but also uncovered a finely tuned but also highly flexible interplay between the different entry glycoproteins. Then, we concentrated on PrV gB by elucidating its 3D-structure and finally succeeded in isolating an autonomously fusogenic herpesvirus gB.
Publications
- (2020) The prefusion structure of herpes simplex virus glycoprotein B. Science advances 6 (39)
Vollmer, B.; Pražák, V.; Vasishtan, D.; Jefferys, E. E.; Hernandez-Duran, A.; Vallbracht, M.; Klupp, B. G.; Mettenleiter, T. C.; Backovic, M.; Rey, F. A.; Topf, M.; Grünewald, K.
(See online at https://doi.org/10.1126/sciadv.abc1726) - (2018), Identification of essential, dispensable and modulatory domains in the core herpesvirus membrane fusion components gB and gH, Mathematischnaturwissenschaftliche Fakultät, Ernst-Moritz-Arndt-Universität, Greifswald
Melina Vallbracht
- (2012). Structure-based mutational analysis of the highly conserved domain IV of glycoprotein H of pseudorabies virus. J Virol 86:8002-8013
Fuchs W, Backovic M, Klupp BG, Rey FA, Mettenleiter TC
(See online at https://doi.org/10.1128/JVI.00690-12) - (2014). The highly conserved proline at position 438 in pseudorabies virus gH is important for regulation of membrane fusion. J Virol 88:13064-13072
Schröter C, Klupp BG, Fuchs W, Gerhard M, Backovic M, Rey FA, Mettenleiter TC
(See online at https://doi.org/10.1128/JVI.01204-14) - (2015), Structure based functional analyses of pseudorabies virus glycoprotein H, Mathematisch-naturwissenschaftliche Fakultät, Ernst-Moritz-Arndt-Universität Greifswald
Sebastian W. Böhm
- (2015). A replication defect of pseudorabies virus induced by targeted α-helix distortion in the syntaxinlike bundle of glycoprotein H (V275P) is corrected by an adjacent compensatory mutation (V271A). J Gen Virol 96:2349-2354
Böhm SW, Backovic M, Klupp BG, Rey FA, Mettenleiter TC, Fuchs W
(See online at https://doi.org/10.1099/vir.0.000161) - (2015). Comparative mutagenesis of pseudorabies virus and Epstein-Barr virus gH identifies a structural determinant within domain III of gH required for surface expression and entry function. J. Virol. 90 Dec 9;90(5):2285-93
Möhl B, Schröter C, Klupp BG, Fuchs W, Mettenleiter TC, Jardetzky TS, Longnecker R
(See online at https://doi.org/10.1128/JVI.03032-15) - (2015). Mutations in pseudorabies virus glycoproteins gB, gD, and gH functionally compensate for the absence of gL. J. Virol. 90, 2264-2272
Schröter C, Vallbracht M, Altenschmidt J, Kargoll S, Fuchs W, Klupp BG, Mettenleiter TC
(See online at https://doi.org/10.1128/JVI.02739-15) - (2015). Structure-based functional analyses of domains II and III of pseudorabies virus glycoprotein H. J Virol 89:1364-1376
Böhm SW, Eckroth E, Backovic M, Klupp BG, Rey FA, Mettenleiter TC, Fuchs W
(See online at https://doi.org/10.1128/JVI.02765-14) - (2016). Functional characterization of glycoprotein H chimeras composed of conserved domains of the pseudorabies virus and herpes simplex virus type 1 homologs. J Virol. 90, 421-432
Böhm S, Backovic M, Klupp BG, Rey FA, Mettenleiter TC, Fuchs W
(See online at https://doi.org/10.1128/JVI.01985-15) - (2017). Functional relevance of the N-terminal domain of pseudorabies virus envelope glycoprotein H and its interaction with glycoprotein L. J. Virol. 91, e00061-17
Vallbracht M., S. Rehwaldt, B.G. Klupp, T.C. Mettenleiter, W. Fuchs
(See online at https://doi.org/10.1128/JVI.00061-17) - (2018). Functional relevance of the transmembrane domain and cytoplasmic tail of the pseudorabies virus glycoprotein H for membrane fusion. J. Virol. 92, e300376-18
Vallbracht M, Fuchs W, Klupp BG, Mettenleiter TC
(See online at https://doi.org/10.1128/JVI.00376-18) - (2018). Functional Role of N-Linked Glycosylation in Pseudorabies Virus Glycoprotein gH. J Virol.; 92(9):e00084-18
Vallbracht M, Rehwaldt S, Klupp BG, Mettenleiter TC, Fuchs W
(See online at https://doi.org/10.1128/JVI.00084-18) - (2018). Structure-Function Dissection of Pseudorabies Virus Glycoprotein B Fusion Loops. J. Virol. 92, e01203-17
Vallbracht M., D. Brun, M. Tassinari, M.-C. Vaney, G. Pehau-Arnaudet, P. Guardado- Calvo, A. Haouz, B.G. Klupp, T.C. Mettenleiter, F.A. Rey, M. Backovic
(See online at https://doi.org/10.1128/JVI.01203-17) - Common characteristics and unique features: a comparison of the fusion machinery of the alphaherpesviruses pseudorabies virus and herpes simplex virus. Adv. Virus Res. 104, 225- 281
Vallbracht M., M. Backovic, B.G. Klupp, F.A. Rey and T.C. Mettenleiter
(See online at https://doi.org/10.1016/bs.aivir.2019.05.007)
