Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Involvement of targeted proteolysis in plant genetic transformation by Agrobacterium

Abstract

Genetic transformation of plant cells by Agrobacterium represents a unique case of trans-kingdom DNA transfer1. During this process, Agrobacterium exports its transferred (T) DNA and several virulence (Vir) proteins into the host cell2, within which T-DNA nuclear import is mediated by VirD2 (ref. 3) and VirE2 (ref. 4) and their host cell interactors AtKAP-α5 and VIP1 (ref. 6), whereas its integration is mediated mainly by host cell proteins7,8,9. The factors involved in the uncoating of T-DNA from its cognate proteins, which occurs before integration into the host genome, are still unknown. Here, we report that VirF—one of the few known exported Vir proteins whose function in the host cell remains unknown—is involved in targeted proteolysis of VIP1 and VirE2. We show that VirF localizes to the plant cell nucleus and interacts with VIP1, a nuclear protein. VirF, which contains an F-box motif10, significantly destabilizes both VIP1 and VirE2 in yeast cells. Destabilization of VIP1 in the presence of VirF was then confirmed in planta. These results suggest that VIP1 and its cognate VirE2 are specifically targeted by the VirF-containing Skp1–Cdc53-cullin–F-box complex for proteolysis. The critical role of proteasomal degradation in Agrobacterium-mediated genetic transformation was also evident from inhibition of T-DNA expression by a proteasomal inhibitor.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Specific interaction between VirF and VIP1 in yeast and plant cells.
Figure 2: VirF-mediated and Skp1-dependent destabilization of VIP1 and VirE2 in yeast cells.
Figure 3: VirF-mediated destabilization of VIP1 in planta.
Figure 4: The effect of 26S proteasome inhibition on T-DNA expression.

Similar content being viewed by others

References

  1. Stachel, S. E. & Zambryski, P. C. Generic trans-kingdom sex? Nature 340, 190–191 (1989)

    Article  ADS  CAS  Google Scholar 

  2. Vergunst, A. C. et al. VirB/D4-dependent protein translocation from Agrobacterium into plant cells. Science 290, 979–982 (2000)

    Article  ADS  CAS  Google Scholar 

  3. Howard, E., Zupan, J., Citovsky, V. & Zambryski, P. C. The VirD2 protein of A. tumefaciens contains a C-terminal bipartite nuclear localization signal: implications for nuclear uptake of DNA in plant cells. Cell 68, 109–118 (1992)

    Article  CAS  Google Scholar 

  4. Citovsky, V., Zupan, J., Warnick, D. & Zambryski, P. C. Nuclear localization of Agrobacterium VirE2 protein in plant cells. Science 256, 1802–1805 (1992)

    Article  ADS  CAS  Google Scholar 

  5. Ballas, N. & Citovsky, V. Nuclear localization signal binding protein from Arabidopsis mediates nuclear import of Agrobacterium VirD2 protein. Proc. Natl Acad. Sci. USA 94, 10723–10728 (1997)

    Article  ADS  CAS  Google Scholar 

  6. Tzfira, T., Vaidya, M. & Citovsky, V. VIP1, an Arabidopsis protein that interacts with Agrobacterium VirE2, is involved in VirE2 nuclear import and Agrobacterium infectivity. EMBO J. 20, 3596–3607 (2001)

    Article  CAS  Google Scholar 

  7. Tzfira, T., Li, J., Lacroix, B. & Citovsky, V. Agrobacterium T-DNA integration: molecules and models. Trends Genet. 20, 375–383 (2004)

    Article  CAS  Google Scholar 

  8. Gelvin, S. B. Agrobacterium-mediated plant transformation: the biology behind the “gene-jockeying” tool. Microbiol. Mol. Biol. Rev. 67, 16–37 (2003)

    Article  CAS  Google Scholar 

  9. Gelvin, S. B. Agrobacterium and plant genes involved in T-DNA transfer and integration. Annu. Rev. Plant Physiol. Plant Mol. Biol. 51, 223–256 (2000)

    Article  CAS  Google Scholar 

  10. Schrammeijer, B. et al. Interaction of the virulence protein VirF of Agrobacterium tumefaciens with plant homologs of the yeast Skp1 protein. Curr. Biol. 11, 258–262 (2001)

    Article  CAS  Google Scholar 

  11. Bundock, P., den Dulk-Ras, A., Beijersbergen, A. & Hooykaas, P. J. J. Trans-kingdom T-DNA transfer from Agrobacterium tumefaciens to Saccharomyces cerevisiae. EMBO J. 14, 3206–3214 (1995)

    Article  CAS  Google Scholar 

  12. Kunik, T. et al. Genetic transformation of HeLa cells by Agrobacterium. Proc. Natl Acad. Sci. USA 98, 1871–1876 (2001)

    Article  ADS  CAS  Google Scholar 

  13. Zupan, J., Muth, T. R., Draper, O. & Zambryski, P. C. The transfer of DNA from Agrobacterium tumefaciens into plants: a feast of fundamental insights. Plant J. 23, 11–28 (2000)

    Article  CAS  Google Scholar 

  14. Tzfira, T. & Citovsky, V. Partners-in-infection: host proteins involved in the transformation of plant cells by Agrobacterium. Trends Cell Biol. 12, 121–129 (2002)

    Article  CAS  Google Scholar 

  15. Melchers, L. S. et al. Octopine and nopaline strains of Agrobacterium tumefaciens differ in virulence; molecular characterization of the virF locus. Plant Mol. Biol. 14, 249–259 (1990)

    Article  CAS  Google Scholar 

  16. Jarchow, E., Grimsley, N. H. & Hohn, B. virF, the host range-determining virulence gene of Agrobacterium tumefaciens, affects T-DNA transfer to Zea mays. Proc. Natl Acad. Sci. USA 88, 10426–10430 (1991)

    Article  ADS  CAS  Google Scholar 

  17. Regensburg-Tuink, A. J. & Hooykaas, P. J. J. Transgenic N. glauca plants expressing bacterial virulence gene virF are converted into hosts for nopaline strains of A. tumefaciens. Nature 363, 69–71 (1993)

    Article  ADS  CAS  Google Scholar 

  18. del Pozo, J. C. & Estelle, M. F-box proteins and protein degradation: an emerging theme in cellular regulation. Plant Mol. Biol. 44, 123–128 (2000)

    Article  CAS  Google Scholar 

  19. Deng, W. et al. VirE1 is a specific molecular chaperone for the exported single-stranded-DNA-binding protein VirE2 in Agrobacterium. Mol. Microbiol. 31, 1795–1807 (1999)

    Article  CAS  Google Scholar 

  20. Hu, C. D., Chinenov, Y. & Kerppola, T. K. Visualization of interactions among bZIP and Rel family proteins in living cells using bimolecular fluorescence complementation. Mol. Cell 9, 789–798 (2002)

    Article  CAS  Google Scholar 

  21. Dommisse, E. M., Leung, D. W. M., Shaw, M. L. & Conner, A. J. Onion is a monocotyledonous host for Agrobacterium. Plant Sci. 69, 249–257 (1990)

    Article  Google Scholar 

  22. Goodin, M. M., Dietzgen, R. G., Schichnes, D., Ruzin, S. & Jackson, A. O. pGD vectors: versatile tools for the expression of green and red fluorescent protein fusions in agroinfiltrated plant leaves. Plant J. 31, 375–383 (2002)

    Article  CAS  Google Scholar 

  23. Gray, W. M., Kepinski, S., Rouse, D., Leyser, O. & Estelle, M. Auxin regulates SCFTIR1-dependent degradation of AUX/IAA proteins. Nature 414, 271–276 (2001)

    Article  ADS  CAS  Google Scholar 

  24. Connelly, C. & Hieter, P. Budding yeast SKP1 encodes an evolutionarily conserved kinetochore protein required for cell cycle progression. Cell 86, 275–285 (1996)

    Article  CAS  Google Scholar 

  25. Tzfira, T., Vaidya, M. & Citovsky, V. Increasing plant susceptibility to Agrobacterium infection by overexpression of the Arabidopsis VIP1 gene. Proc. Natl Acad. Sci. USA 99, 10435–10440 (2002)

    Article  ADS  CAS  Google Scholar 

  26. Lee, D. H. & Goldberg, A. L. Proteasome inhibitors: valuable new tools for cell biologists. Trends Cell Biol. 8, 397–403 (1998)

    Article  CAS  Google Scholar 

  27. Narasimhulu, S. B., Deng, X.-B., Sarria, R. & Gelvin, S. B. Early transcription of Agrobacterium T-DNA genes in tobacco and maize. Plant Cell 8, 873–886 (1996)

    Article  CAS  Google Scholar 

  28. Otten, L. et al. Restoration of virulence of vir region mutants of A. tumefaciens strain B6S3 by coinfection with normal and mutant Agrobacterium strains. Mol. Gen. Genet. 195, 159–163 (1984)

    Article  CAS  Google Scholar 

  29. Schrammeijer, B., Hemelaar, J. & Hooykaas, P. J. The presence and characterization of a virF gene on Agrobacterium vitis Ti plasmids. Mol. Plant Microbe Interact. 11, 429–433 (1998)

    Article  CAS  Google Scholar 

  30. Nagai, H. & Roy, C. R. Show me the substrates: modulation of host cell function by type IV secretion systems. Cell. Microbiol. 5, 373–383 (2003)

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank S. Gelvin for VirF and Agrobacterium strains, T. Durfee for ASK1, and M. Goodin for pGDR. We are also grateful to R. Sternglanz and A. Neiman for their suggestions and discussion. The work in our laboratory is supported by grants from the National Institutes of Health, National Science Foundation, US Department of Agriculture, US–Israel Bi-national Science Foundation (BSF), and US–Israel Bi-national Agricultural Research and Development Fund (BARD) to V.C., and by grants from BARD and Human Frontiers Science Program to T.T.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Tzvi Tzfira.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Tzfira, T., Vaidya, M. & Citovsky, V. Involvement of targeted proteolysis in plant genetic transformation by Agrobacterium. Nature 431, 87–92 (2004). https://doi.org/10.1038/nature02857

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature02857

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing