The Potato virus X TGBp3 protein associates with the ER network for virus cell-to-cell movement

Virology. 2003 Apr 25;309(1):135-51. doi: 10.1016/s0042-6822(02)00102-2.


Potato virus X (PVX) TGBp3 is required for virus cell-to-cell movement. Cell-to-cell movement of TGBp3 was studied using biolistic bombardment of plasmids expressing GFP:TGBp3. TGBp3 moves between cells in Nicotiana benthamiana, but requires TGBp1 to move in N. tabacum leaves. In tobacco leaves GFP:TGBp3 accumulated in a pattern resembling the endoplasmic reticulum (ER). To determine if the ER network is important for GFP:TGBp3 and for PVX cell-to-cell movement, a single mutation inhibiting membrane binding of TGBp3 was introduced into GFP:TGBp3 and into PVX. This mutation disrupted movement of GFP:TGBp3 and PVX. Brefeldin A, which disrupts the ER network, also inhibited GFP:TGBp3 movement in both Nicotiana species. Two deletion mutations, that do not affect membrane binding, hindered GFP:TGBp3 and PVX cell-to-cell movement. Plasmids expressing GFP:TGBp2 and GFP:TGBp3 were bombarded to several other PVX hosts and neither protein moved between adjacent cells. In most hosts, TGBp2 or TGBp3 cannot move cell-to-cell.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Biolistics
  • Endoplasmic Reticulum / virology*
  • Green Fluorescent Proteins
  • Luminescent Proteins / genetics
  • Molecular Sequence Data
  • Potexvirus / physiology*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Solanum tuberosum / virology
  • Tobacco / virology
  • Viral Nonstructural Proteins / chemistry
  • Viral Nonstructural Proteins / genetics
  • Viral Nonstructural Proteins / metabolism*


  • Luminescent Proteins
  • Recombinant Fusion Proteins
  • Viral Nonstructural Proteins
  • Green Fluorescent Proteins