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A non-proteolytic role for ubiquitin in Tat-mediated transactivation of the HIV-1 promoter

Abstract

The human immunodeficiency virus type 1 (HIV-1) encodes a potent transactivator, Tat, which functions through binding to a short leader RNA, called transactivation responsive element (TAR). Recent studies suggest that Tat activates the HIV-1 long terminal repeat (LTR), mainly by adapting co-activator complexes, such as p300, PCAF and the positive transcription elongation factor P-TEFb, to the promoter. Here, we show that the proto-oncoprotein Hdm2 interacts with Tat and mediates its ubiquitination in vitro and in vivo. In addition, Hdm2 is a positive regulator of Tat-mediated transactivation, indicating that the transcriptional properties of Tat are stimulated by ubiquitination. Fusion of ubiquitin to Tat bypasses the requirement of Hdm2 for efficient transactivation, supporting the notion that ubiquitin has a non-proteolytic function in Tat-mediated transactivation.

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Figure 1: Modification of the HIV-1 transactivator, Tat, by ubiquitination.
Figure 2: Hdm2 mediates Tat ubiquitination in vitro and in vivo.
Figure 3: Lys 71 of Tat is involved in Hdm2-mediated ubiquitination.
Figure 4: Hdm2 does not target Tat for degradation.
Figure 5: Hdm2 enhances Tat-mediated transactivation of the HIV-1 LTR.

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References

  1. Thomas, D. & Tyers, M. Transcriptional regulation: Kamikaze activators. Curr. Biol. 10, R341–R343 (2000).

    Article  CAS  Google Scholar 

  2. Conaway, R.C., Brower, C.S. & Conaway, J.W. Emerging roles of ubiquitin in transcription regulation. Science 296, 1254–1258 (2002).

    Article  CAS  Google Scholar 

  3. Muratani, M. & Tansey, W.P. How the ubiquitin–proteasome system controls transcription. Nature Rev. Mol. Cell Biol. 4, 192–201 (2003).

    Article  CAS  Google Scholar 

  4. Salghetti, S.E., Caudy, A.A., Chenoweth, J.G. & Tansey, W.P. Regulation of transcriptional activation domain function by ubiquitin. Science 293, 1651–1653 (2001).

    Article  CAS  Google Scholar 

  5. Kiernan, R.E. et al. Interaction between cyclin T1 and SCF(SKP2) targets CDK9 for ubiquitination and degradation by the proteasome. Mol. Cell Biol. 21, 7956–7970 (2001).

    Article  CAS  Google Scholar 

  6. Winston, J.T. et al. The SCFβ–TRCP–ubiquitin ligase complex associates specifically with phosphorylated destruction motifs in IκBα and β-catenin and stimulates IκBα ubiquitination in vitro. Genes Dev. 13, 270–283 (1999).

    Article  CAS  Google Scholar 

  7. Lassot, I. et al. ATF4 degradation relies on a phosphorylation-dependent interaction with the SCF(βTrCP) ubiquitin ligase. Mol. Cell Biol. 21, 2192–2202 (2001).

    Article  CAS  Google Scholar 

  8. Leveillard, T. & Wasylyk, B. The MDM2 C-terminal region binds to TAFII250 and is required for MDM2 regulation of the cyclin A promoter. J. Biol. Chem. 272, 30651–30661 (1997).

    Article  CAS  Google Scholar 

  9. Daujat, S., Neel, H. & Piette, J. MDM2: life without p53. Trends Genet. 17, 459–464 (2001).

    Article  CAS  Google Scholar 

  10. Gu, L., Findley, H.W. & Zhou, M. MDM2 induces NF–κB/p65 expression transcriptionally through Sp1-binding sites: a novel, p53-independent role of MDM2 in doxorubicin resistance in acute lymphoblastic leukemia. Blood 99, 3367–3375 (2002).

    Article  CAS  Google Scholar 

  11. Wei, P., Garber, M.E., Fang, S.M., Fischer, W.H. & Jones, K.A. A novel CDK9-associated C-type cyclin interacts directly with HIV-1 Tat and mediates its high-affinity, loop-specific binding to TAR RNA. Cell 92, 451–462 (1998).

    Article  CAS  Google Scholar 

  12. Haupt, Y., Maya, R., Kazaz, A. & Oren, M. Mdm2 promotes the rapid degradation of p53. Nature 387, 296–299 (1997).

    Article  CAS  Google Scholar 

  13. Legube, G. et al. Tip60 is targeted to proteasome-mediated degradation by Mdm2 and accumulates after UV irradiation. EMBO J. 21, 1704–1712 (2002).

    Article  CAS  Google Scholar 

  14. Pickart, C.M. Ubiquitin in chains. Trends Biochem. Sci. 25, 544–548 (2000).

    Article  CAS  Google Scholar 

  15. Li, C.J., Wang, C., Friedman, D.J. & Pardee, A.B. Reciprocal modulations between p53 and Tat of human immunodeficiency virus type 1. Proc. Natl Acad. Sci. USA 92, 5461–5464 (1995).

    Article  CAS  Google Scholar 

  16. Bres, V. et al. Differential acetylation of Tat coordinates its interaction with the co- activators cyclin T1 and PCAF. EMBO J. 21, 6811–6819 (2002).

    Article  CAS  Google Scholar 

  17. Huang, L.M., Joshi, A., Willey, R., Orenstein, J. & Jeang, K.T. Human immunodeficiency viruses regulated by alternative trans-activators: genetic evidence for a novel non-transcriptional function of Tat in virion infectivity. EMBO J. 13, 2886–2896 (1994).

    Article  CAS  Google Scholar 

  18. Ferdous, A., Gonzalez, F., Sun, L., Kodadek, T. & Johnston, S.A. The 19S regulatory particle of the proteasome is required for efficient transcription elongation by RNA polymerase II. Mol. Cell 7, 981–991 (2001).

    Article  CAS  Google Scholar 

  19. Gonzalez, F., Delahodde, A., Kodadek, T. & Johnston, S.A. Recruitment of a 19S proteasome subcomplex to an activated promoter. Science 296, 548–550 (2002).

    Article  CAS  Google Scholar 

  20. Nelbock, P., Dillon, P.J., Perkins, A. & Rosen, C.A. A cDNA for a protein that interacts with the human immunodeficiency virus Tat transactivator. Science 248, 1650–1653 (1990).

    Article  CAS  Google Scholar 

  21. Shibuya, H. et al. New human gene encoding a positive modulator of HIV Tat-mediated transactivation. Nature 357, 700–702 (1992).

    Article  CAS  Google Scholar 

  22. Ohana, B. et al. The type 1 human immunodeficiency virus Tat binding protein is a transcriptional activator belonging to an additional family of evolutionarily conserved genes. Proc. Natl Acad. Sci. USA 90, 138–412 (1993).

    Article  CAS  Google Scholar 

  23. DeMartino, G.N. et al. Identification, purification, and characterization of a PA700-dependent activator of the proteasome. J. Biol. Chem. 271, 3112–3118 (1996).

    Article  CAS  Google Scholar 

  24. Glickman, M.H. et al. A subcomplex of the proteasome regulatory particle required for ubiquitin-conjugate degradation and related to the COP9-signalosome and eIF3. Cell 94, 615–623. (1998).

    Article  CAS  Google Scholar 

  25. Rubin, D.M. et al. Identification of the gal4 suppressor Sug1 as a subunit of the yeast 26S proteasome. Nature 379, 655–657 (1996).

    Article  CAS  Google Scholar 

  26. Treier, M., Staszewski, L.M. & Bohmann, D. Ubiquitin-dependent c-Jun degradation in vivo is mediated by the delta domain. Cell 78, 787–798 (1994).

    Article  CAS  Google Scholar 

  27. Kiernan, R.E. et al. HIV-1 tat transcriptional activity is regulated by acetylation. EMBO J. 18, 6106–6118 (1999).

    Article  CAS  Google Scholar 

  28. Ward, C.L., Omura, S. & Kopito, R.R. Degradation of CFTR by the ubiquitin–proteasome pathway. Cell 83, 121–127 (1995).

    Article  CAS  Google Scholar 

  29. Johnson, E.S., Ma, P.C., 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 

  30. Clavel, F. & Charneau, P. Fusion from without directed by human immunodeficiency virus particles. J. Virol. 68, 1179–1185 (1994).

    CAS  PubMed  PubMed Central  Google Scholar 

  31. Benkirane, M. et al. Activation of integrated provirus requires histone acetyltransferase. p300 and P/CAF are coactivators for HIV-1 Tat. J. Biol Chem. 273, 24898–24905 (1998).

    Article  CAS  Google Scholar 

  32. Lisztwan, J. et al. Association of human CUL-1 and ubiquitin-conjugating enzyme CDC34 with the F-box protein p45(SKP2): evidence for evolutionary conservation in the subunit composition of the CDC34-SCF pathway. EMBO J. 17, 368–383 (1998).

    Article  CAS  Google Scholar 

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Acknowledgements

We wish to thank O. Bensaude and J. Piette for helpful discussions, B. Réant for technical assistance, H. Neel and J. Piette for the gift of Hdm2 expression plasmid, D. Trouche for HA-p53 plasmid, R. Kopito for pHis–Ub and pHis–UBK48R, R. Benarous for anti-βTrCP antibody. This work was supported by grants from the Agence Nationale de Recherche sur le SIDA (ANRS), Human Frontier Science Program, Minister de la Recherche (ACI) to M.B., by Agence de Recherche contre le Cancer (ARC), ANRS and SIDACTION (S.E.), by CNRS and ARC (O.C), by the German-Israeli Foundation for Scientific Research and Development (M.S.) and by the European Commission (QLGI-CT-2001-02026) to M.S and O.C. R.K. was supported by ANRS–SIDACTION, O.P. by a ARC post-doctoral fellowship and V.B. by a MERT scholarship.

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Correspondence to Monsef Benkirane.

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Brès, V., Kiernan, R., Linares, L. et al. A non-proteolytic role for ubiquitin in Tat-mediated transactivation of the HIV-1 promoter. Nat Cell Biol 5, 754–761 (2003). https://doi.org/10.1038/ncb1023

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