Sub-cellular localization of the 25-kDa protein encoded in the triple gene block of potato virus X

Virology. 1993 Nov;197(1):166-75. doi: 10.1006/viro.1993.1577.


The 25-kDa protein of potato virus X (PVX) is encoded by the 5' open reading frame of the overlapping triple gene block, has a GKS sequence motif characteristic of nucleotide binding proteins, and is thought to play a role in movement between cells. We have produced a polyclonal antibody to the 25-kDa protein to investigate its synthesis and intracellular location. On Western blots of infected tissue extracts this antibody detected a single major protein of the expected mobility, produced earlier than the viral coat protein in infected protoplasts and located predominantly in the 1000 g pellet fraction of infected cells. Immunogold labeling of thin sections of infected tissue revealed that the 25-kDa protein is associated with the cytoplasmic inclusion bodies characteristic of PVX infections, but not with the cell wall or plasmodesmata. Therefore, although mutational studies indicate a role for the 25-kDa protein in the cell to cell movement of viral infection it is unlikely to act in precisely the same manner as the other well-characterized movement proteins of tobacco mosaic and cowpea mosaic viruses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antibodies
  • Base Sequence
  • Blotting, Western
  • Capsid / analysis
  • Capsid / biosynthesis
  • Cloning, Molecular
  • Genes, Viral*
  • Microscopy, Immunoelectron
  • Molecular Sequence Data
  • Molecular Weight
  • Oligodeoxyribonucleotides
  • Open Reading Frames*
  • Plants, Toxic
  • Potexvirus / genetics*
  • Potexvirus / metabolism
  • Potexvirus / ultrastructure
  • Protoplasts / microbiology
  • Protoplasts / ultrastructure
  • RNA, Viral / biosynthesis
  • Recombinant Fusion Proteins / biosynthesis
  • Tobacco
  • Viral Proteins / analysis
  • Viral Proteins / biosynthesis*


  • Antibodies
  • Oligodeoxyribonucleotides
  • RNA, Viral
  • Recombinant Fusion Proteins
  • Viral Proteins