Cleavage of the human respiratory syncytial virus fusion protein at two distinct sites is required for activation of membrane fusion

Proc Natl Acad Sci U S A. 2001 Aug 14;98(17):9859-64. doi: 10.1073/pnas.151098198. Epub 2001 Aug 7.

Abstract

Preparations of purified full-length fusion (F) protein of human respiratory syncytial virus (HRSV) expressed in recombinant vaccinia-F infected cells, or of an anchorless mutant (F(TM(-))) lacking the C-terminal 50 amino acids secreted from vaccinia-F(TM(-))-infected cells contain a minor polypeptide that is an intermediate product of proteolytic processing of the F protein precursor F0. N-terminal sequencing of the intermediate demonstrated that it is generated by cleavage at a furin-motif, residues 106-109 of the F sequence. By contrast, the F1 N terminus derives from cleavage at residue 137 of F0 which is also C-terminal to a furin recognition site at residues 131-136. Site-directed mutagenesis indicates that processing of F0 protein involves independent cleavage at both sites. Both cleavages are required for the F protein to be active in membrane fusion as judged by syncytia formation, and they allow changes in F structure from cone- to lollipop-shaped spikes and the formation of rosettes by anchorless F.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Cricetinae
  • Cytopathogenic Effect, Viral
  • Endopeptidases / metabolism
  • Giant Cells
  • Humans
  • Kidney
  • Membrane Fusion / physiology*
  • Mesocricetus
  • Microscopy, Electron
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Protein Conformation
  • Protein Precursors / chemistry
  • Protein Precursors / metabolism*
  • Protein Processing, Post-Translational*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / physiology
  • Respiratory Syncytial Viruses / genetics
  • Respiratory Syncytial Viruses / physiology*
  • Structure-Activity Relationship
  • Viral Fusion Proteins / chemistry
  • Viral Fusion Proteins / genetics
  • Viral Fusion Proteins / physiology*
  • Viral Fusion Proteins / ultrastructure
  • Viral Proteins / chemistry
  • Viral Proteins / genetics
  • Viral Proteins / physiology*
  • Viral Proteins / ultrastructure

Substances

  • Protein Precursors
  • Recombinant Fusion Proteins
  • Viral Fusion Proteins
  • Viral Proteins
  • Endopeptidases