Abstract
Live-cell fluorescence microscopy was used to investigate the third triple gene block protein (TGB3) of potato mop-top pomovirus and its role in assisted targeting of TGB2 to plasmodesmata (PD). Wild-type and mutant TGB3 proteins were expressed under the control of the 35 S promoter or from a virus reporter clone. Assisted targeting of TGB2 to PD was optimal when the proteins were expressed from a bicistronic plasmid in the relative ratios expected in a virus infection, suggesting that excess TGB3 inhibited PD localisation. Contrary to the generally accepted view, bimolecular fluorescence complementation showed that the TGB3 N terminus is located in the cytosol. Mutational analysis to dissect TGB3 sub domain functions showed that PD targeting was mediated by a composite signal comprising an ER-lumenal tyrosine-based motif and the C-terminal transmembrane domain. Mutation of either of these domains also abolished cell-to-cell movement of the virus. The results are discussed in the context of TGB3 membrane topology. (C) 2010 Elsevier Inc. All rights reserved.
Original language | English |
---|---|
Pages (from-to) | 41-51 |
Number of pages | 11 |
Journal | Virology |
Volume | 402 |
Issue number | 1 |
DOIs | |
Publication status | Published - 20 Jun 2010 |
Keywords
- Triple gene block
- Hordei-like virus movement proteins
- Bimolecular fluorescence complementation
- Green fluorescent protein
- Red fluorescent protein
- TRIPLE GENE BLOCK
- TOBACCO-MOSAIC-VIRUS
- POA SEMILATENT VIRUS
- SUBCELLULAR-LOCALIZATION
- CELL MOVEMENT
- PLANT
- RNA
- PREDICTION
- TOPOLOGY
- REVEALS