Spike protein fusion peptide and feline coronavirus virulence

Emerg Infect Dis. 2012 Jul;18(7):1089-95. doi: 10.3201/eid1807.120143.


Coronaviruses are well known for their potential to change their host or tissue tropism, resulting in unpredictable new diseases and changes in pathogenicity; severe acute respiratory syndrome and feline coronaviruses, respectively, are the most recognized examples. Feline coronaviruses occur as 2 pathotypes: nonvirulent feline enteric coronaviruses (FECVs), which replicate in intestinal epithelium cells, and lethal feline infectious peritonitis viruses (FIPVs), which replicate in macrophages. Evidence indicates that FIPV originates from FECV by mutation, but consistent distinguishing differences have not been established. We sequenced the full genome of 11 viruses of each pathotype and then focused on the single most distinctive site by additionally sequencing hundreds of viruses in that region. As a result, we identified 2 alternative amino acid differences in the putative fusion peptide of the spike protein that together distinguish FIPV from FECV in >95% of cases. By these and perhaps other mutations, the virus apparently acquires its macrophage tropism and spreads systemically.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cats
  • Coronavirus Infections / virology
  • Coronavirus, Feline / genetics
  • Coronavirus, Feline / metabolism
  • Coronavirus, Feline / pathogenicity*
  • Feline Infectious Peritonitis / virology
  • Genome, Viral
  • Membrane Glycoproteins / genetics*
  • Membrane Glycoproteins / metabolism
  • Molecular Sequence Data
  • Mutation*
  • Peptides / genetics*
  • Recombinant Fusion Proteins / genetics*
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Spike Glycoprotein, Coronavirus
  • Viral Envelope Proteins / genetics*
  • Viral Envelope Proteins / metabolism
  • Virulence / genetics


  • Membrane Glycoproteins
  • Peptides
  • Recombinant Fusion Proteins
  • Spike Glycoprotein, Coronavirus
  • Viral Envelope Proteins