The Potato virus X TGBp3 protein associates with the ER network for virus cell-to-cell movement.
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.
Krishnamurthy
Konduru
K
Oklahoma State University, Department of Entomology and Plant Pathology, Stillwater, OK 74078, USA.
Heppler
Marty
M
Mitra
Ruchira
R
Blancaflor
Elison
E
Payton
Mark
M
Nelson
Richard S
RS
Verchot-Lubicz
Jeanmarie
J
D000595:Amino Acid Sequence; D019470:Biolistics; D004721:Endoplasmic Reticulum / Q000821:virology*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D017863:Potexvirus / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000821:virology; D014026:Nicotiana / Q000821:virology; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D017361:Viral Nonstructural Proteins; D049452:Green Fluorescent Proteins