Back to overview

Efficient replication of a paramyxovirus independent of full zippering of the fusion protein six-helix bundle domain.

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Author Brindley Melinda A, Plattet Philippe, Plemper Richard Karl,
Project Unraveling Paramyxovirus Cell Entry
Show all

Original article (peer-reviewed)

Journal Proceedings of the National Academy of Sciences of the United States of America
Volume (Issue) 111(36)
Page(s) 3795 - 804
Title of proceedings Proceedings of the National Academy of Sciences of the United States of America
DOI 10.1073/pnas.1403609111


Enveloped viruses such as HIV and members of the paramyxovirus family use metastable, proteinaceous fusion machineries to merge the viral envelope with cellular membranes for infection. A hallmark of the fusogenic glycoproteins of these pathogens is refolding into a thermodynamically highly stable fusion core structure composed of six antiparallel α-helices, and this structure is considered instrumental for pore opening and/or enlargement. Using a paramyxovirus fusion (F) protein, we tested this paradigm by engineering covalently restricted F proteins that are predicted to be unable to close the six-helix bundle core structure fully. Several candidate bonds formed efficiently, resulting in F trimers and higher-order complexes containing covalently linked dimers. The engineered F complexes were incorporated into recombinant virions efficiently and were capable of refolding into a postfusion conformation without temporary or permanent disruption of the disulfide bonds. They efficiently formed fusion pores based on virus replication and quantitative cell-to-cell and virus-to-cell fusion assays. Complementation of these F mutants with a monomeric, fusion-inactive F variant enriched the F oligomers for heterotrimers containing a single disulfide bond, without affecting fusion complementation profiles compared with standard F protein. Our demonstration that complete closure of the fusion core does not drive paramyxovirus entry may aid the design of strategies for inhibiting virus entry.