This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Li, X. H.
Right arrow Articles by Carrington, J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Li, X. H.
Right arrow Articles by Carrington, J. C.

 Previous Article  |  Next Article 

J. Virol., 02 1997, 1598-1607, Vol 71, No. 2
Copyright © 1997, American Society for Microbiology

Functions of the tobacco etch virus RNA polymerase (NIb): subcellular transport and protein-protein interaction with VPg/proteinase (NIa)

XH Li, P Valdez, RE Olvera and JC Carrington
Department of Biology, Texas A&M University, College Station 77843, USA.

The NIb protein of tobacco etch potyvirus (TEV) possesses several functions, including RNA-dependent RNA polymerase and nuclear translocation activities. Using a reporter protein fusion strategy, NIb was shown to contain two independent nuclear localization signals (NLS I and NLS II). NLS I was mapped to a sequence within amino acid residues 1 to 17, and NLS II was identified between residues 292 and 316. Clustered point mutations resulting in substitutions of basic residues within the NLSs were shown previously to disrupt nuclear translocation activity. These mutations also abolished TEV RNA amplification when introduced into the viral genome. The amplification defects caused by each NLS mutation were complemented in trans within transgenic cells expressing functional NIb, although the level of complementation detected for each mutant differed significantly. Combined with previous results (X. H. Li and J. C. Carrington, Proc. Natl. Acad. Sci. USA 92:457-461, 1995), these data suggest that the NLSs overlap with essential regions necessary for NIb trans-active function(s). The fact that NIb functions in trans implies that it must interact with one or more other components of the genome replication apparatus. A yeast two-hybrid system was used to investigate physical interactions between NIb and several other TEV replication proteins, including the multifunctional VPg/proteinase NIa and the RNA helicase CI. A specific interaction was detected between NIa and NIb. Deletion of any of five regions spanning the NIb sequence resulted in NIb variants that were unable to interact with NIa. Clustered point mutations affecting the conserved GDD motif or NLS II within the central region of NIb, but not mutations affecting NLS I near the N terminus, reduced or eliminated the interaction. The C-terminal proteinase (Pro) domain of NIa, but not the N-terminal VPg domain, interacted with NIb. The effects of NIb mutations within NLS I, NLS II, and the GDD motif on the interaction between the Pro domain and NIb were identical to the effects of these mutations on the interaction between full-length NIa and NIb. These data are compatible with a model in which NIb is directed to replication complexes through an interaction with the Pro domain of NIa.


This article has been cited by other articles:

  • Rajamaki, M.-L., Valkonen, J. P.T. (2009). Control of Nuclear and Nucleolar Localization of Nuclear Inclusion Protein a of Picorna-Like Potato virus A in Nicotiana Species. Plant Cell 21: 2485-2502 [Abstract] [Full Text]  
  • Hafren, A., Makinen, K. (2008). Purification of viral genome-linked protein VPg from potato virus A-infected plants reveals several post-translationally modified forms of the protein. J. Gen. Virol. 89: 1509-1518 [Abstract] [Full Text]  
  • Khan, M. A., Miyoshi, H., Ray, S., Natsuaki, T., Suehiro, N., Goss, D. J. (2006). Interaction of Genome-linked Protein (VPg) of Turnip Mosaic Virus with Wheat Germ Translation Initiation Factors eIFiso4E and eIFiso4F. J. Biol. Chem. 281: 28002-28010 [Abstract] [Full Text]  
  • Kang, S.-H., Lim, W.-S., Hwang, S.-H., Park, J.-W., Choi, H.-S., Kim, K.-H. (2006). Importance of the C-terminal domain of soybean mosaic virus coat protein for subunit interactions. J. Gen. Virol. 87: 225-229 [Abstract] [Full Text]  
  • Puustinen, P., Makinen, K. (2004). Uridylylation of the Potyvirus VPg by Viral Replicase NIb Correlates with the Nucleotide Binding Capacity of VPg. J. Biol. Chem. 279: 38103-38110 [Abstract] [Full Text]  
  • Vetter, G., Hily, J.-M., Klein, E., Schmidlin, L., Haas, M., Merkle, T., Gilmer, D. (2004). Nucleo-cytoplasmic shuttling of the beet necrotic yellow vein virus RNA-3-encoded p25 protein. J. Gen. Virol. 85: 2459-2469 [Abstract] [Full Text]  
  • Jakubiec, A., Notaise, J., Tournier, V., Hericourt, F., Block, M. A., Drugeon, G., van Aelst, L., Jupin, I. (2004). Assembly of Turnip Yellow Mosaic Virus Replication Complexes: Interaction between the Proteinase and Polymerase Domains of the Replication Proteins. J. Virol. 78: 7945-7957 [Abstract] [Full Text]  
  • Leonard, S., Viel, C., Beauchemin, C., Daigneault, N., Fortin, M. G., Laliberte, J.-F. (2004). Interaction of VPg-Pro of Turnip mosaic virus with the translation initiation factor 4E and the poly(A)-binding protein in planta. J. Gen. Virol. 85: 1055-1063 [Abstract] [Full Text]  
  • Dunoyer, P., Thomas, C., Harrison, S., Revers, F., Maule, A. (2004). A Cysteine-Rich Plant Protein Potentiates Potyvirus Movement through an Interaction with the Virus Genome-Linked Protein VPg. J. Virol. 78: 2301-2309 [Abstract] [Full Text]  
  • Yambao, Ma. L. M., Masuta, C., Nakahara, K., Uyeda, I. (2003). The central and C-terminal domains of VPg of Clover yellow vein virus are important for VPg-HCPro and VPg-VPg interactions. J. Gen. Virol. 84: 2861-2869 [Abstract] [Full Text]  
  • Merits, A., Rajamaki, M.-L., Lindholm, P., Runeberg-Roos, P., Kekarainen, T., Puustinen, P., Makelainen, K., Valkonen, J. P. T., Saarma, M. (2002). Proteolytic processing of potyviral proteins and polyprotein processing intermediates in insect and plant cells. J. Gen. Virol. 83: 1211-1221 [Abstract] [Full Text]  
  • Guo, D., Rajamäki, M.-L., Saarma, M., Valkonen, J. P. T. (2001). Towards a protein interaction map of potyviruses: protein interaction matrixes of two potyviruses based on the yeast two-hybrid system. J. Gen. Virol. 82: 935-939 [Abstract] [Full Text]  
  • López, L., Urzainqui, A., Domínguez, E., García, J. A. (2001). Identification of an N-terminal domain of the plum pox potyvirus CI RNA helicase involved in self-interaction in a yeast two-hybrid system. J. Gen. Virol. 82: 677-686 [Abstract] [Full Text]  
  • Léonard, S., Plante, D., Wittmann, S., Daigneault, N., Fortin, M. G., Laliberté, J.-F. (2000). Complex Formation between Potyvirus VPg and Translation Eukaryotic Initiation Factor 4E Correlates with Virus Infectivity. J. Virol. 74: 7730-7737 [Abstract] [Full Text]  
  • Daros, J.-A., Schaad, M. C., Carrington, J. C. (1999). Functional Analysis of the Interaction between VPg-Proteinase (NIa) and RNA Polymerase (NIb) of Tobacco Etch Potyvirus, Using Conditional and Suppressor Mutants. J. Virol. 73: 8732-8740 [Abstract] [Full Text]