Evidence for a new viral late-domain core sequence, FPIV, necessary for budding of a paramyxovirus

J Virol. 2005 Mar;79(5):2988-97. doi: 10.1128/JVI.79.5.2988-2997.2005.


Enveloped virus budding has been linked to both the ubiquitin-proteasome pathway and the vacuolar protein-sorting pathway of cells. We show here for the paramyxovirus SV5 that proteasome inhibitors and expression of dominant-negative VPS4(E228Q) ATPase blocks budding. The SV5 matrix (M) protein lacks previously defined late domains (e.g., P[T/S]AP, PPxY, YPDL) that recruit cellular factors. We identified a new motif for budding (core sequence FPIV) that can compensate functionally for lack of a PTAP late domain in budding human immunodeficiency virus type 1 virus-like particles (VLPs). Mutagenesis experiments suggest the more general sequence O-P-x-V. The proline residue was found to be critically important for function of this sequence, as substitution of this proline in the SV5 M protein resulted in poor budding of SV5 VLPs and failure of recombinant SV5 virus to replicate normally. Adaptation of mutant virus occurred rapidly, resulting in new proline residues elsewhere in the M protein. We hypothesize that these proline residues act to partially restore virus budding by generation of new motifs that act as suboptimal late domains.

Publication types

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

MeSH terms

  • ATPases Associated with Diverse Cellular Activities
  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / physiology
  • Amino Acid Sequence
  • Amino Acid Substitution
  • Cell Line
  • Endosomal Sorting Complexes Required for Transport
  • Gene Products, gag / genetics
  • Gene Products, gag / physiology
  • HIV-1 / genetics
  • HIV-1 / physiology
  • Humans
  • Microscopy, Electron
  • Molecular Sequence Data
  • Mutation
  • Paramyxovirinae / drug effects
  • Paramyxovirinae / genetics*
  • Paramyxovirinae / physiology*
  • Proline / chemistry
  • Protease Inhibitors / pharmacology
  • Repressor Proteins / genetics
  • Repressor Proteins / physiology
  • Sequence Homology, Amino Acid
  • Vacuolar Proton-Translocating ATPases
  • Vesicular Transport Proteins
  • Viral Matrix Proteins / chemistry
  • Viral Matrix Proteins / genetics
  • Viral Matrix Proteins / physiology
  • Virus Assembly / drug effects
  • Virus Assembly / genetics
  • Virus Assembly / physiology


  • Endosomal Sorting Complexes Required for Transport
  • Gene Products, gag
  • Protease Inhibitors
  • Repressor Proteins
  • Vesicular Transport Proteins
  • Viral Matrix Proteins
  • Proline
  • Adenosine Triphosphatases
  • Vacuolar Proton-Translocating ATPases
  • ATPases Associated with Diverse Cellular Activities
  • VPS4A protein, human