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Autoregulation of an E2 enzyme by ubiquitin-chain assembly on its catalytic residue

Nature Cell Biology volume 9, pages 422–427 (2007)Cite this article

Abstract

Cells have quality-control mechanisms to recognize non-native protein structures and either help the proteins fold or promote their degradation1,2. Ubiquitin-conjugating enzymes (E2s) and ubiquitin ligases (E3s) work together to assemble polyubiquitin chains on misfolded or misassembled proteins, which are then degraded by the proteasome3,4. Here, we find that Ubc7, a yeast E2, can itself undergo degradation when its levels exceed that of its binding partner Cue1, a transmembrane protein that tethers Ubc7 to the endoplasmic reticulum5,6. Unassembled, and thus mislocalized, Ubc7 is targeted to the proteasome by Ufd4, a homologous to E6-AP C-terminus (HECT)-class E3. Ubc7 is autoubiquitinated by a novel mechanism wherein the catalytic cysteine, instead of a lysine residue, provides the polyubiquitin chain acceptor site, and this cysteine-linked chain functions as a degradation signal. The polyubiquitin chain can also be transferred to a lysine side chain, suggesting a mechanism for polyubiquitin chain assembly that precedes substrate modification.

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Figure 1: Proteasome-dependent degradation of unassembled Ubc7.
Figure 2: Ubc7 degradation depends on the HECT E3 ligase Ufd4.
Figure 3: Degradation of Ubc7 depends on its catalytic cysteine residue.
Figure 4: Formation of polyubiquitin chains on the Ubc7 catalytic cysteine.

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References

  1. Wickner, S., Maurizi, M. R. & Gottesman, S. Posttranslational quality control: folding, refolding, and degrading proteins. Science 286, 1888–1893 (1999).

    Article  CAS  Google Scholar 

  2. Meusser, B., Hirsch, C., Jarosch, E. & Sommer, T. ERAD: the long road to destruction. Nature Cell Biol 7, 766–772 (2005).

    Article  CAS  Google Scholar 

  3. Hochstrasser, M. Ubiquitin-dependent protein degradation. Annu. Rev. Genetics 30, 405–439 (1996).

    Article  CAS  Google Scholar 

  4. Pickart, C. M. Mechanisms underlying ubiquitination. Annu. Rev. Biochem. 70, 503–533 (2001).

    Article  CAS  Google Scholar 

  5. Biederer, T., Volkwein, C. & Sommer, T. Role of Cue1p in ubiquitination and degradation at the ER surface. Science 278, 1806–1809 (1997).

    Article  CAS  Google Scholar 

  6. Gardner, R. G., Shearer, A. G. & Hampton, R. Y. In vivo action of the HRD ubiquitin ligase complex: mechanisms of endoplasmic reticulum quality control and sterol regulation. Mol. Cell Biol. 21, 4276–4291 (2001).

    Article  CAS  Google Scholar 

  7. Biederer, T., Volkwein, C. & Sommer, T. Degradation of subunits of the Sec61p complex, an integral component of the ER membrane, by the ubiquitin-proteasome pathway. EMBO J. 15, 2069–2076 (1996).

    Article  CAS  Google Scholar 

  8. Laney, J. D., Mobley, E. F. & Hochstrasser, M. The short-lived Matα2 transcriptional repressor is protected from degradation in vivo by interactions with its corepressors Tup1 and Ssn6. Mol. Cell Biol. 26, 371–380 (2006).

    Article  CAS  Google Scholar 

  9. Friedlander, R., Jarosch, E., Urban, J., Volkwein, C. & Sommer, T. A regulatory link between ER-associated protein degradation and the unfolded-protein response. Nature Cell Biol. 2, 379–384 (2000).

    Article  CAS  Google Scholar 

  10. Johnson, E. S., Ma, P. C. M., Ota, I. M. & Varshavsky, A. A proteolytic pathway that recognizes ubiquitin as a degradation signal. J. Biol. Chem. 270, 17442–17456 (1995).

    Article  CAS  Google Scholar 

  11. Xie, Y. & Varshavsky, A. UFD4 lacking the proteasome-binding region catalyses ubiquitination but is impaired in proteolysis. Nature Cell Biol. 4, 1003–1007 (2002).

    Article  CAS  Google Scholar 

  12. Walter, J., Urban, J., Volkwein, C. & Sommer, T. Sec61p-independent degradation of the tail-anchored ER membrane protein Ubc6p. EMBO J. 20, 3124–3131 (2001).

    Article  CAS  Google Scholar 

  13. Rape, M. & Kirschner, M. W. Autonomous regulation of the anaphase-promoting complex couples mitosis to S-phase entry. Nature 432, 588–595 (2004).

    Article  CAS  Google Scholar 

  14. Yamanaka, A. et al. Cell cycle-dependent expression of mammalian E2-C regulated by the anaphase-promoting complex/cyclosome. Mol. Biol. Cell 11, 2821–2831 (2000).

    Article  CAS  Google Scholar 

  15. Machida, Y. J. et al. UBE2T is the E2 in the Fanconi anemia pathway and undergoes negative autoregulation. Mol. Cell 23, 589–596 (2006).

    Article  CAS  Google Scholar 

  16. Wu, P. Y. et al. A conserved catalytic residue in the ubiquitin-conjugating enzyme family. EMBO J. 22, 5241–5250 (2003).

    Article  CAS  Google Scholar 

  17. Cook, W. J., Martin, P. D., Edwards, B. F., Yamazaki, R. K. & Chau, V. Crystal structure of a class I ubiquitin conjugating enzyme (Ubc7) from Saccharomyces cerevisiae at 2.9 angstroms resolution. Biochem 36, 1621–1627 (1997).

    Article  CAS  Google Scholar 

  18. Swanson, R., Locher, M. & Hochstrasser, M. A conserved ubiquitin ligase of the nuclear envelope/endoplasmic reticulum that functions in both ER-associated and Matα2 repressor degradation. Genes Dev. 15, 2660–2674 (2001).

    Article  CAS  Google Scholar 

  19. Ciechanover, A. & Ben-Saadon, R. N-terminal ubiquitination: more protein substrates join in. Trends Cell Biol. 14, 103–106 (2004).

    Article  CAS  Google Scholar 

  20. Coulombe, P., Rodier, G., Bonneil, E., Thibault, P. & Meloche, S. N-Terminal ubiquitination of extracellular signal-regulated kinase 3 and p21 directs their degradation by the proteasome. Mol. Cell Biol. 24, 6140–6150 (2004).

    Article  CAS  Google Scholar 

  21. Hodgins, R. R. W., Ellison, K. S. & Ellison, M. J. Expression of a ubiquitin derivative that conjugates to protein irreversibly produces phenotypes consistent with a ubiquitin deficiency. J. Biol. Chem. 267, 8807–8812 (1992).

    CAS  PubMed  Google Scholar 

  22. Hodgins, R., Gwozd, C., Arnason, T., Cummings, M. & Ellison, M. J. The tail of a ubiquitin-conjugating enzyme redirects multi-ubiquitin chain synthesis from the lysine 48-linked configuration to a novel nonlysine-linked form. J. Biol. Chem. 271, 28766–28771 (1996).

    Article  CAS  Google Scholar 

  23. Lin, Y., Hwang, W. C. & Basavappa, R. Structural and functional analysis of the human mitotic-specific ubiquitin-conjugating enzyme, UbcH10. J. Biol. Chem. 277, 21913–21921 (2002).

    Article  CAS  Google Scholar 

  24. Cadwell, K. & Coscoy, L. Ubiquitination on nonlysine residues by a viral E3 ubiquitin ligase. Science 309, 127–130 (2005).

    Article  CAS  Google Scholar 

  25. Haldeman, M. T., Xia, G., Kasperek, E. M. & Pickart, C. M. Structure and function of ubiquitin conjugating enzyme E2-25K: the tail is a core-dependent activity element. Biochem. 36, 10526–10537 (1997).

    Article  CAS  Google Scholar 

  26. Hochstrasser, M. Lingering mysteries of ubiquitin-chain assembly. Cell 124, 27–34 (2006).

    Article  Google Scholar 

  27. Chen, P., Johnson, P., Sommer, T., Jentsch, S. & Hochstrasser, M. Multiple ubiquitin-conjugating enzymes participate in the in vivo degradation of the yeast MATα2 repressor. Cell 74, 357–369 (1993).

    Article  CAS  Google Scholar 

  28. Ravid, T., Kreft, S. G. & Hochstrasser, M. Membrane and soluble substrates of the Doa10 ubiquitin ligase are degraded by distinct pathways. EMBO J. 25, 533–543 (2006).

    Article  CAS  Google Scholar 

  29. Varelas, X., Ptak, C. & Ellison, M. J. Cdc34 self-association is facilitated by ubiquitin thiolester formation and is required for its catalytic activity. Mol. Cell Biol. 23, 5388–5400 (2003).

    Article  CAS  Google Scholar 

  30. Deng, M. & Hochstrasser, M. Spatially regulated ubiquitin ligation by an ER/nuclear membrane ligase. Nature 443, 827–831 (2006).

    Article  CAS  Google Scholar 

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Acknowledgements

We thank: Y. Reiss, G. Jona and O. Kerscher for valuable discussions; Y. Xie for providing the yeast deletion strain plate; Y. Xie, R. Hampton and T. Sommer for plasmids; and T. Biederer, R. Felberbaum, G. Jona and S. Kreft for comments on the manuscript. This work was supported by a U.S. National Institutes of Health (NIH) grant (GM046904) to M.H.

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  1. Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, 06520, CT, USA

    Tommer Ravid & Mark Hochstrasser

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  1. Tommer Ravid
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T.R. performed all the experiments, and T.R. and M.H. conceived and designed the experiments and wrote the paper.

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Correspondence to Mark Hochstrasser.

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The authors declare no competing financial interests.

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Supplementary Figures S1, S2, S3, S4, Supplementary Table and Methods (PDF 483 kb)

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Ravid, T., Hochstrasser, M. Autoregulation of an E2 enzyme by ubiquitin-chain assembly on its catalytic residue. Nat Cell Biol 9, 422–427 (2007). https://doi.org/10.1038/ncb1558

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